Veraxis
Linux Mint. Easy to set up, reasonably easy to use, and used by enough people that a quick internet search should probably turn up results of people who have run into similar issues if you ever have a problem.
I second @Hellmo_Luciferrari@lemm.ee 's suggestion of Arch/KDE. I cannot think of a time when I have had to go outside of pacman/yay or setup a custom repo. I don't use them personally, but the AUR even has -git versions of many packages if I needed to have the absolutely down-to-the-minute latest version of something, but even the official repos are rarely far behind in my experience. Fractional scaling seems to work fine on my 2560x1600 display. VScodium works fine when I tested it, but I do not use it regularly enough to really have a strong opinion on it.
That is a lot of RAM. Only a quad-core processor, but I imagine should still be fine for general-purpose desktop use.
What would you want it to do? Honestly I would call that over-specced for something like a file server and would probably consume a lot of power if left on all the time. Maybe a media server which can use the discrete GPU for video encoding?
How so? I have never found installing yay difficult, and using it is essentially the same as pacman with the addition of aur packages. What issues have you run into?