I feel like upscaling from 144p would be terrible. 360p might be more doable i think

As someone that is very new to FOSS, especially on mobile, it sounds like F-Droid is a Play Store replacement. Where can I download that safely?

Linux Mint felt like a really good start for me. Its a nice transition from Windows because you still get a lot of functions that can be done outside of the command line. There's a GUI for system updates, driver updates, and an app store of sorts. The interface is also just generally not all that different from Windows.

In my experience, I didnt have any issues running games on Mint. I was using a pretty powerful rig with AMD hardware, which tends to play nicer with Linux, but from what I've heard Mint seems to do well with gaming.

To play games, you'll obviously need Steam with Proton enabled. I picked the latest full release version and it generally worked pretty good with most games. Some games that wont work with Steam might need a separate app called Lutris. For me this was just Battlefield 4, which also worked fine through Lutris. You can check ProtonDB to see if the games you wanna play will work.

If you use Nvidia, I've heard good things about Pop!OS but i havent used it myself.

Good luck finding a distro that works for you!