Yup, Linux can look like whatever you want. I made my old Ubuntu install look like Windows 7 for the lulz once, but now I'm too lazy to change the defaults.
KDE Plasma + Klassy can do that. I think you can pull off a Win7 look with just those two.
KDE Plasma can get you far with its customization options, and Klassy adds more customization on top of that, and adds the translucent/transparent effects you need to emulate the Win7 look.
Old Gnome2-era themes will always win out imo. I tried looking for neat Plasma themes but a lot of em are just very basic colour swaps, nothing out there
KDE themes are a mixed bag for me. On one hand, they can potentially provide theming for little to no effort on my part (provided I do find a pre-made theme to my liking), but on the other, I had more luck with mixing and matching (and a lot of tweaking) different theme components (that is: color theme, application style, plasma style, window decorations, icon theme, cursor theme, etc). It's a lot of work, and the result might not exactly be coherent, but you can really tweak quite a lot.
I haven't really tried emulating the win7 look and feel by customizing KDE Plasma, but I think it's possible. Someone in this comment chain claimed there's a Win7 theme available, albeit not pulling it off perfectly. I guess that can be used as a starting point.
Just a heads up while the look might be easy to emulate the feel part will at best be close. Which is actually good because a lot about that is rather shoddy in windows... and focussing on getting what you had with windows might make you miss stuff you didn't think you wanted. Like MMB click on scrollbars, or dragging and resizing windows with Super+LMB/RMB
Thanks. I've been a daily Linux user since 2013, distro-hopping between every environment and whatnot, these days mostly on i3/tmux/vim on Kali for HackTheBox.
I use Windows 10 on my main PC for media/flight/race/milsimming with an Aero skin that gets pretty darn close, without using WindowBlinds, using SecureUxTheme tool, cracked StartIsBack and some theme I got off the Frutiger Aero subreddit, looks great with WACUP, 8Gadgets, Aerochat and some Windhawk mods like the old Win7 Taskbar Clock (instead of the W10 XAML one)