Best Laptop for Linux

Kali isn't meant to be a desktop OS. Use it only in VM or in a spare rig. It is meant to be a toolbox. So dual boot it with your daily driver OS or use in a VM.
Your Mac can take Linux just well: https://djharper.dev/post/2020/06/07/running-linux-on-my-macbook/
For your 300 bucks budget look nothing else than Thinkpad T480 or HP Dev One. T480 will need replacement batteries if not replaced yet.
- so tired of people recommending thinkpads when there are much better options. the fact the control and alt key were swapped for years is enough to never get ibm or Lenovo.
- Thanks! Think I'll try installing Linux on a VM first and see how it runs on my Mac. If performance is slow ill look into the Thinkpad.
  
  See if you can run off a live USB instead of in a VM if you're testing for performance. VM is likely gonna perform worse than if you were to install it on your hardware. Usually when you make a USB installer for a distro you can boot to it and use the desktop like normal off the USB rather than running the install.

For under $300, I would go for a used Thinkpad. I got a T460s for a few hundred bucks that runs linux wonderfully (jesus was the pre-installed Windows slow though). Linux usually runs much better than Windows on old low-end hardware. That 2015 MacBook has an Intel processor, so I would try Linux on that first as it might be more powerful than what you can afford to buy.
Kali is not an OS you would want to use for your main desktop, if you need those security tools you can run them in a virtual machine / live usb. I see you've tried to base your distro choice off of what you intend to do in school, which I think is a mistake. Choose your distro based off of the merits of the distro itself, as once you get past the package manager and release cycle, you can get the same experience on any distribution.
Before choosing a distro I would make sure you know the answer to these questions (in terms of what you want):
Stable or rolling release model?
Package manager (apt, dnf, pacman, zypper, etc.)
and these about your desktop environment:
What desktop environment (or standalone window manager) do you want to use?
Do I want to use Wayland or X11 as a display server? Does it matter to me which I use?
Does your distro have a spin preinstalled with your desktop environment of choice?
^ Also, if you are unsure about what some of this means, feel free to ask.
- Thinkpads are great simply because so many Linux devs use them. Likely that any kernel issues are fixed, especially if not brand new.
- I second the used ThinkPad. I installed Ubuntu and it works great.
- Thanks for the detailed response! I think I'll take the advice that some others and that you've mentioned also. I have an extra USB drive laying around so I'm going to try and install Linux and run it through a VM on my Mac first. If all runs well, then great! If not, I'll look into the Thinkpad.
  I actually am unsure of what numbers 2,4, and 5 mean in your response. I'm coming from a non-tech field, but have a huge interest and am trying to build up my knowledge on all of the technical terms especially when it comes to Linux.
  Thanks again!
  
  No problem! About the USB drive, running it in a VM would not tell you anything about how it will run on the Macbook itself. I would recommend booting into the usb in a 'live environment'. Essentially, you boot into the linux operating system off of the usb and are able to play around and use it in a non-persistent environment. You simply plug in the usb and select it as your boot device. If you decide you like it and it works well, installing should be as easy and following the steps in the installer. The reason running a VM wouldn't tell you anything is that VMs are virtualizated, meaning they don't directly run off of your computers hardware. The drivers used for virtual machines are their own unique virtualization drivers, so for these reasons running linux VMs is separate from linux compatibility on bare metal.
  Here is an explanation of those questions:
  This is less important when choosing your first distro, but some users have varying preferences on package managers. The package manager is responsible for installing and updating everything on your system (everything; applications, libraries, and the kernel) that has been installed via the package manager. Some package managers are distro-agnostic and are installed alongside your distro's package manager, like Nix or Guix, although you don't really have to worry about these. The package manager is baked into the distro you used and cannot be changed, and some distros have the same package manager. For an example of a preference, dnf (Fedora's package manager) commands are much more verbose than pacman (Arch's package manager) commands.
  To show what I mean, here's the command for installing a package with each:
  dnf install
  <package>
  pacman -S
  <package>
  Some find the letter arguments of pacman more confusing.
  An example of a preference I've observed is that I prefer dnf's search results over apt's (Debian's package manager), although apt search is much faster than dnf's. Little things like these don't make a huge difference, but the package manager is something you will interact with a lot, so watching a quick video or guide on a distro's package manager can't hurt.
  A display server is responsible for displaying your graphical environment. If you have your laptop open and you're looking at a few windows, the display server is responsible for the placement, size, and content of the windows. Everything graphic on a linux system is handled by the display server. You have chosen to get into linux in the middle of a sort of transition period from the older X11 display server to the newer Wayland display server. Wayland is newer, more secure, and overall snappier / less screen-tear-ey. X11 is older and not receiving development, but is tried and tested, much better for accessibility needs than Wayland, and more "self-contained" (i.e X11 is not just one program, it contains many programs to make interacting with the graphic environment easy and consistent. Wayland leaves these integrations in the hand of each "compositor")
  Desktop environments and window managers will either:
  Support Wayland and X11
  Support only X11 (Many X11 only examples have forks that support Wayland)
  Support only Wayland
  As for your applications, some may or may not support running on Wayland natively, which is a non-issue as the program XWayland will automatically run X11 only programs through X11 on your Wayland desktop.
  TL;DR on the display server section here: One day you will have to use Wayland, but today is not that day. If Wayland covers all the functionality you need, and you do not use NVIDIA (Wayland on NVIDIA is not in a good state currently), I would go with that. If accessibility or easy software compatibility is your aim, go X11.
  This one is easy, let's say you've decided you 100% want to use the Cinnamon desktop environment. Linux Mint has three spins (All that 'spin' means is a version of the distro with that desktop environment pre-installed): Cinnamon, MATE, and XFCE, however not all distros offer a Cinnamon spin. If you wanted to use a distro that does not offer a spin of the desktop environment you'd like, download the 'minimal' iso for that distro. Some distros call this iso a different name or might only offer a 'server' iso that fulfills the same purpose, but basically you'll boot into a tty (terminal prompt) and you can simply install the desktop environment you want via the package manager.
  I hope this helps and isn't confusing!
- Because you left such a good answer I have a question related to number 4. Any idea how KDE Plasma is working with Wayland these days? I've been to their showstopper page from time to time but haven't really asked the question to anyone who may have tried it recently.
  
  I use it both in my work machine and home desktop. It's generally fine and just works on my home box (AMD graphics). The work machine has a HiDPI 4k panel which I've set to 200% scaling - that, along with nVidia graphics has a few issues (especially with Java and electron based apps), but it's been getting better in the few months I've had it, e.g. the latest Firefox fixed some scaling issues.

I think my next one will be a https://frame.work There is also an overview of supported systems: https://frame.work/en/en/linux
- I've got a 13" 13th gen on order, really digging the idea of upgrading easily. I hope they release a 2k 120hz display someday, that's the only thing I'm not digging about the framework

Interested in Linux? Getting a degree in Cyber Security?
A used ThinkPad. The older the better
- This with libre boot.
  
  https://minifree.org/ 👀
- I second this! If all you need is low end and Linux compatible laptop, Thinkpads are, almost annoyingly, regarded as the tinkerer/hacker Laptop. After some research (one search on ebay) they are going for very cheap, far within your budget.
  I did a little research and found this which states that for the graphical installation, it will take "at least 2 GB of RAM and 20 GB of disk space" and in some cases certain apps/programs recommend 8 GB of RAM.
  I recommend 8 GB of RAM for now and a 128 GB hard drive. If you can get a smaller drive go for it, but just stick with the main brands like Crucial or Western Digital when it comes to drives. I recently had my SSD corrupted in my thinkpad because the previous owner bought a cheap drive that randomly disconnected at times.
  I believe RAM is replaceable and upgradeable in most thinkpads, but verify that before purchase, it'll save you the disappointment of being stuck with 8 GB of RAM.
  I hope this helped :)
  
  Thanks for the information! I ended up going with a t480 and installed Pop! OS on it. I"m enjoying it so far!
- Thanks for the advice!

Purchase an extra memory stick for your existing laptop and run your tools on a virtual machine. Very few utilities require an physical machine.
Edit: MBP 2015 is not memory upgradable. But I believe my statement is still your best option.
- I just looked up a guide on how to install VM on a Mac and it seems pretty straightforward. Seems like I could at least give it a try since I have an extra USB drive laying around. Thanks for the suggestion!

whatever you get, don't sleep on the ethernet port, very few cheap laptops come with it nowadays, and that ill greatly reduce your selection
- Personally. I don't need an Ethernet port. If I'm getting a cheap laptop I won't be doing any gaming on it and don't need low-latency or maximum bandwith internet. Just use WIFI
  
  his interest toward cybersecurity means he probably is going to have to at least connect and reconnect to different networks, which will be a pain when not required to be wifi

Thinkpad for compatibility

If you're trying to optimize your cost, you might get away for free by installing a virtual machine on your existing MacBook :)

Your best bet is probably to get a refurbished thinkpad. I've seen X1 Carbons (their ultra thin Macbook-like line of ultrabooks) for 250 bucks on backmarket. That's the 2016 model (G5) and not in the best tier of refurbishment (So there might be some small scratches on the chassis) but the hardware should be more than enough for your usecase. Linux generally speaking does very well on low end hardware and thinkpads are especially well supported.
One thing though: DON'T INSTALL KALI ON YOUR DEVICE, IT'S NOT DESIGNED FOR THAT. Or rather it wasn't. Originally Kali was meant to be run of a thumb drive only. By now enough people have attempted to install it that the devs have given up and provide a bare metal edition. That is just Debian with some stuff preinstalled though. There is very little secret source (like the "undercover mode"). You should go with debian and try to build your toolbox as you go. This way you will get a better insight into your Linux system because it forces you to set up everything yourself
- Thanks for the advice! First time hearing of Debian, I'll check it out!

Tuxedo is the linux brand of the german company "Schenker".

Definitely the framework laptop, check it out, it's completely modular, thin, light, performant, and insanely repairable, they even include qr codes on every part to help replace them and they will ship the device to you with no os for a discount and disassembled for a much bigger discount.

Anything that doesn't have an NVIDIA GPU is Linux-friendly.

I have a cheap Acer laptop with AMD and it works great. I'm dual booting with Windows. I do remember having to struggle with the install though. I had to turn off secure boot and can't remember what else. Good luck.
- In my experience, Acer build quality has been shoddy. There's a reason everyone recommends used Thinkpads. They have great build quality so you can get more years out of a used one than a new cheap consumer laptop.
  
  Acer is not business grade for sure. But other than the dumb power cable I've been happy. The power cable looks like it was designed to break, lol. I put electrical tape on it to prevent it from destroying itself. With cheap laptops they do some silly things like, crappy outdated screens with low resolution or super low brightness. Soldered ram with no is little upgrade. No usb-c charging or display.
  Good luck

With that budget you should be able to get your hands on a machine with plenty of power. My recomendation would go to a lenovo t480/t480s. I was planning to buy one of those for myself but my current laptop is still good enough. Regardless of the device you choose, I would recomend portability over power: power efficient i5 4 cores, 8gb (idealy 16gb) ram, ssd storage, lightweight and good battery.
To answer your last question, you shouldn't be concerned about performance. Linux can give life to old hardware, but you're not really looking at old hardware.
As a cybersec student myself, I would suggest starting out with a generic linux distro and just install the tools you need as you go. If you really need kali, install it in a vm. I say this because I expect you'll use Linux as your daily driver, and Kali is NOT mean to be a daily driver, but a tool for when you need it. And "when you need it" will come with experience I guess.
- Thanks, I'll have to look into installing Kali in a vm. I've seen distros such as Linux Mint being discussed. Would that be a good daily driver to use?
  
  Mint is a very good start! If you don't like it you can always switch later

does Linux run fine on low-end laptops?
Linux runs fine on a potato lol

My t480 came in right at that price, and is doing very well for word processing and media consumption.
But Linux is almost always going to do well on low end stuff compared to Windows.
- I ended up going with the t480 and I recently installed Pop! OS on it!
  
  Sweet :)

Ive had an excellent time with the thinkpad e14 w/ ryzen 5500u. Worked flawlessly with both void and gentoo. Same drivers and config as any ryzen based desktop CPU.
Best part is the price - you can snag one used for 300~ USD and it can do everything my desktop can save for cutting edge AAA gaming or server hosting

Ive had an excellent time with the thinkpad e14 w/ ryzen 5500u. Worked flawlessly with both void and gentoo. Same drivers and config as any ryzen based desktop CPU.
Best part is the price - you can snag one used for 300~ USD and it can do everything my desktop can save for cutting edge AAA gaming or server hosting

I've always stuck to Thinkpads for Linux -- especially the T series is incredibly solid. That said, you really shouldn't have an issue with a 2015 MacBook.

I'd check local places like offerup. can get business laptops for cheap when places refresh. there are a few people around me selling 3-4 year old dells with i5/i7, nvme, etc. take a Linux USB and install it on site before you buy to test. they're more than enough specwise for daily use or testing. often sub $300

Currently I think the most eco-friendly option is a Framework.
- @mrshy @KuroJ Agreed, you also have the @slimbook and the @tuxedocomputers #computer which are well suited for running #linux since they ship with it out of the box !
  
  Another option would be to get a laptop which is verified to work with most or all of QubesOS security features.

Just to reinforce what all the thread is saying: used Thinkpad in ebay. I would search for a x270/x280/t470/t480. This depends in screen size.
Why these models? They are the last ones that allow you ti upgrade your RAM, so when you have a bit more money you can upgrade. Also, these are old but not ancient, so they can still be relevant for some time.
On the other hand, if you have more budget, the best Linux laptops are the frame.work, but they're expensive, although they're reparable and upgradable, so I guess that depends on how you see it.
Finally, Kali is not a daily use distro. If you have time to waste (or invest) then you can go hardcore and straight to Arch Linux. If you want to have an easier journey you can start with PopOs!
Good luck on your journey!!