#computer shopping

I'm looking at buying a desktop computer, and I DESPERATELY need help figuring out what to get. My budget is really tight, I haven't had a desktop of any kind for almost a decade, and I'm completely lost looking at my options. Anybody want to help a confused elder millennial get out of the dark ages?

My current budget is a firm $500, unfortunately, but I don't know how much that can buy technology wise these days. I'm willing to spend that 500 on a very basic no-frills machine and upgrade it as I go, if someone has the patience to walk me through it.

I want a machine that's

- Able to record, import, edit and export media, video, audio or both, without choking.

- Able to run Twitch, OBS, and Steam simultaneously, without choking.

- Compatible with the Arturia midi keyboard I bought in uhhhh 2017? 18? I never managed to get it working before my last computer melted.

- Running a stripped down OS that's both flexible and intuitive. (I'm terrified of Linux, as I've failed to get Mint running several times in the past. I hate trying to function on Mac. In a perfect world, I would run Windows 7 forever. Is there a Libre OS, in the same vein as LibreOffice and LibreWolf? Open source Alternatives welcome, if they don't require a ton of tweaks to run things like Steam, OBS, Ableton, or Sony Vegas.)

Pipe dream: Built-in optical CDR/W & DVD drive. Do they exist anymore? Can I install one myself later, without the risk of bricking the whole thing?

Confused: RAM? Graphics card? Sound card? SSD? Processors? Help me, I've been living in Android World for almost a decade.

Stuff I know I don't want:

- LEDs everywhere

- "Highly customizeable," as in "You'll need a comp sci degree to get it to run an *.exe, but it's Soooo intuitive~~~"