Have you ever played an instrument? How good did you get?

I have zero musical ability so I’m in awe of anyone that has any
Unless you literally have congenital amusia (a.k.a. tone deafness), there is no such thing as zero musical ability. About 1-2% of people are thought to have congenital amusia, so it's not out of the question but ... uh ... can you distinguish songs when you hear them? If so, you likely don't have it. (There is expressive amusia, but it's the least prevalent of the types.)
So, barring amusia, anybody has musical ability. All you need is exposure, practice time, and the patience to learn. If you really want to learn, pick up a simple instrument (a wind instrument with a fipple mouthpiece like a recorder, tin whistle, or ocarina; a kalimba; a small, cheap keyboard) and just start. Keep it cheap because if you don't enjoy it you don't want to have spent a lot of money.
- Tom Morello, who wrote some of the most kickass rock songs of the 90's, has openly stated that he had absolutely zero natural talent. He starting playing guitar at the age of 17, which is usually considered much too late. He practiced 8 hours a day, while ALSO being a Freshman at Harvard. He said he drove his roommates in his dorm insane.
  So, yes, what you wrote is true. What matters is... how bad do you want it?

I play guitar.
I'm good enough to pick out most songs by ear, and could play in a hobbyist cover band, and not completely suck.
Which is OK with me, I just like to play.

I taught myself guitar and while I have some bad habits as a result of that and am probably not as good as I ought to be for how long I've been playing, I am pretty good nowadays. I can play most things that I want to play, it's only really the tougher end of prog metal stuff that I enjoy but which is beyond my reach.
I've learned a bit of bass guitar too, since most of the hand movements and shapes from guitar can be transferred across, you just have to cover a little more distance with each movement. Learning bass was much more an exercise in thinking about the instrument differently and understanding how to apply it in a musical context than it was a matter of learning new ways of moving my hands.
I'm attempting to learn piano at the moment, but it's coming along slowly. I had started learning violin beforehand, but I realised that I needed to be much better at reading sheet music than I was if I was to play much violin, and I figured piano would be an easier way to learn that. I can read sheet music, just not nearly well enough, and that becomes something of an obstacle on an unfamiliar instrument. With guitar, tabs got me through the early stages and after that I was able to do things by ear for the most part, so I never properly developed the sheet music skills.
- A lot of very good guitarists (Alex Lifeson leaps to mind) are almost entirely self-taught.
  
  Lifeson is fantastic. I'm glad I got to see him performing live while I could. But yeah, self-teaching is absolutely valid. I just should have been more disciplined and methodical about how I did it. It has worked out okay, though; I'm good enough to make myself happy
- Glad to hear you picked up the bass with the right mindset coming from guitar. A lot of people think it’s a 1:1 but bass is such a different beast for sure
  
  It is quite frustrating to see other guitarists just play bass as if it was just a big guitar. It makes for very dull bass parts. I suppose I had something of an advantage though. One of my friends is an exceptionally proficient jazz and funk bassist, so I was exposed to a lot of what bass could be

I was in school in a time period when they understood that learning music would make us learn everything a little better.
Thus, every child could play the Recorder and the Ukulele, and then we specialized the next year with saxophones and clarinets and trumpets and some poor kid who had to walk a mile home with a fucking tuba every 2 days because he was too close for the bus. Sorry Jason.

I play mainly guitar and I’m really good at it. I also play bass and am really good at it. I also play piano/keyboard and am pretty good at it. I’m working on getting better at drums now. I used to play trumpet in school but don’t really remember much of it anymore. I’ve also played a bunch of different stringed instruments here and there just messing around, the concept is usually similar to guitar with an open tuning
- Wow you're really good at it! It's impressive
  
  Thanks! I absolutely love the craft and have dedicated a lot of time to it!

I can play (with various degrees of skill):
Flute
Harmonica
Mouth harp
Guitar
Theramin
Recorder
Ocarina
Piano
The harmonica is what I can play the best, that also feels like it takes skill. Mouth harp is barely an instrument lol
Worst at guitar; but it is also the one I've taken up most recently.
- Theramin? "One of these things is not like the others!"
  I wish I could afford one of those. They look fascinating.

I played cornet (small trumpet) then baritone (small euphonium) in a brass-band basically from primary school up until I graduated university and moved oversea. I went to conservatorium through all the amateur levels, got my certificate degree and then stopped classes. My town band would also compete regionally and nationally, and get decent results!
I guess I got good enough to play properly in my town band and be first chair of the baritone section, but I was never passionate enough to go pro, or even to join a more important band.

Play guitar since like 12, not very good. But got pretty good at the electric bass in my teens, even got in a band

I used to play bugle in a local orchestra from ages 11-14 or so but I had to give it up because I couldn't read music well enough. Turned out to be a part of my dyscalculia somehow. Wish I could've been talented. Ah well.
- How does the dyscalculia effect you? It's one of the conditions that gets almost no awareness
  
  In school it meant I had a lot of difficulty with maths. I initially studied Latin in highschool but that came paired with 5-8 hours of maths which I couldn't handle, so I dropped down to humanities. When it was time to choose a major in college I went with journalism because, well, no math, right? But my real dream job was to go into academia which I never did because I just assumed I couldn't possibly hack it.
  So now I've worked in customer service for the last twenty years. There's not a single day that passes that I don't regret I didn't try harder with maths or took a major I actually wanted to do instead of something to pay the bills.
  So in terms of actual impact, dyscalculia hardly comes into play at all since everyone has access to a calculator 100% of the time (despite what my teachers would say back then). But in terms of how it impacted the flow of my life, it's pretty tragic. It cost me so many opportunities which I'll never get back. Don't make my mistake.

Trumpet: Played from I was 8 to when I was 16. I was pretty decent.
Guitar: Started at 9 and still play to this day. I'm alright, but I'm not as good as I should/could be.
Piano/keyboard/organ: Started at 7, and I've been noodling around with it ever since. Not very good at all. I mostly use it as a reference instrument when I need to figure out and/experiment with chords and scales.

I started off with an accordion at age 4. (Yes, before I actually went to school!) I got good enough at it that by age 16 I got 4th place in a Baden-Württemberg state level championship.
But before that, at around the age of 8, I'd actually paused at the accordion (for complicated reasons stemming from how early I'd started and the workload that was expected of me at the music school) and started playing the organ instead, with home lessons. I got pretty good at it before a move to Germany (and subsequent re-uptake of the accordion) ended that around the age of 12.
While I was in Germany, parallel to continuing with my accordion, I joined my school band. There really wasn't a place for accordion in that curriculum so I picked up the saxophone and got almost as good with it as I was with my accordion.
I then, in my final year of school, at age 17, I had to make an important choice for my future: basically did I want to study music and go pro, or did I want to study business and marketing? I chose the latter because I had this inkling that I would not do well as a pro musician.
That being said, I still played music. I still had my accordion (the saxophone was the school's and I wasn't going to spend the cash to buy one for myself: them things are EXPENSIVE yo!), and I had a knack for picking up other instruments. Even in school I'd already picked up the clarinet because it was similar enough to a saxophone I could get to the point of playing decently with little effort.
I did drop the accordion after about ten years, though, because it was just too big to constantly lug around as I bounced around from apartment to apartment and city to city. I donated it to an old man who was a pro player (retired) and bored in his old folk's home.
Since then I've picked up the following woodwinds to the point that I can reliably play simple tunes at least:
dizi (I have at least 5 in various keys)
xiao (I have 4 in various keys and fingerings)
guanzi (only one; fiendishly difficult to play!)
bawu (one end blown, one side blown, one double-barrelled side blown)
hulusi (one wood, one "single-belly" gourd)
LittleSax (one 8-hole, one 10-hole)
(This may sound ridiculous, but really the fingerings are so similar that it's trivial to learn a new one's and instead you focus on the embouchure.)
I've also picked up a couple of woodwind-adjacent instruments:
ocarina (one "serious" transverse one and a bunch of cheap novelty pendant ones, most of which I give as gifts to students)
xun (another fiendishly difficult one; a clay 8-hole, a clay 10-hole, and three 10-hole bamboo ones in various keys)
Finally I've lately become quite enamoured of the kalimba and have five of those (17-key box, 17-key solid acrylic, 24-key, 34-key chromatic, and 42-key chromatic, the last three in solid wood). I initially got the first one while bored during the COVID-19 lockdowns and it was so much fun I got a few more.
- Accordion always seems to me like it has a crazy amount of stuff to do at once. Not only have both hands got all the complexity of a piano, the left hand is doing it in a much smaller space, you have to manage the bellows as well and you also can't really see what your fingers are doing
  
  The left hand has all the buttons on a piano accordion, but also has cheats. The second line from the top is the tonic and the top line is the third from that tonic. The tones go up by fifths along the length.
  The third gives you the major chord of the tonic, the fourth gives you the minor chord, the fifth gives you the dominant 7th, and the sixth (on the one I owned) gives you the diminished 7th. So you have automation for chord accompaniment and rarely have to play anything of significant complexity on the left.
  Which leaves the bellows and half a piano on the right. 🤣

I’ve played guitar and trombone. Only did trombone for like half a year, and was too grossed out by the spit valve lol so I stuck with guitar.
I can read tabs but can’t read music and can replicate the tabs with some practice.
But I go years without playing and then randomly pick it up so I’ve never gotten good at it. Just a fun hobby and fun to know a little here and there.

The glass armonica. I'm fluent.

Guitars and vocals were my main two instruments. In bands that I was in, I did just vocals (mix of clean singing and screaming type stuff). But I also did occasional solo gigs with acoustic guitar, mainly covers like Working Class Hero and Redemption Song and shit. Although ultimately my music career went nowhere slowly and I haven't played guitar or sang for a few years.
Although I have been starting to get the itch again. I've currently got 3 acoustic guitars in my cupboard that need some repairs but I'm thinking of picking up a cheap electric or maybe even the bass some time.

Well, I played recorder in elementary school. I was not the worst in class, but not exactly in the middle either.
I tried guitar, but the only one I had access to was horrible, so I could never really play it, and gave up after it became clear that nothing else was going to be available to me. Which kinda sucked because I had started to figure things out, despite the shitty guitar, but trying to use any of it was just not good.
I guess I could have modified the guitar, but I was like 16 and had no idea that was even possible then, much less how to do it.
Also, my chorus teacher tried to teach me enough piano so that I wouldn't have to sing. That's because I suck at singing lol. I didn't even sign up for the class, I got shunted there after the classes I chose filled up. I had picked art as the primary option, latin as the secondary, and band as the third. Chorus wasn't anything I was into at all, and I knew I couldn't sing worth a damn.
After the teacher discovered that I couldn't sing for shit, she tried to get me moved, and couldn't. Then she tried teaching me some piano enough to bang out some stuff during class, and I was vaguely interested, but you can't learn piano quickly, and that's what would have been needed.
So, I learned to lip sync!
Later on, I picked up some very basic drumming fucking around with friends. Not enough to call myself a drummer, but enough that I can kinda get the job done in a pinch. Enough to keep a beat going for practice or just fucking around, and to recognize I'd need a lot more practice if I ever wanted to be serious with it.
I've figured out that I could probably have learned an instrument, before my arthritis got bad, but that's also why I'm not upset I didn't go hard after any of it; having put in that work and then losing the benefit of it to arthritis? I'd be pissed