Well, moving to linux suggests you‘re trying to use it on your desktop, yet the post body suggests you‘re looking for a server.
These are two very distinct projects with vastly different difficulty and complexity levels.
I first made a homeserver for automation (homeassistant), streaming (plex), cloud (nextcloud) and some others. This was fairly straightforward and helped me learn the intricacies of the commandline from the ground up. I have no desktop environment on said server so I was forced to learn to ssh into it and my understanding grew quite fast.
After 2 yrs of this server running more or less without hickups (some minor mistakes made by me), I switched my desktop and lo and behold, it was quite a mess. Desktop linux is infinitely more complex than server linux and the amount of things that can (and probably will) go wrong multiply.
Hardwarewise, you can use the shittiest machine you can find for linux since windows is much more demanding. I even put lubuntu (bc lxqt) on a laptop from 2008 and its glorious! To get streaming in hd pr 4k you‘ll need a fairly strong machine with at least 4 cores and maybe 8-16 gbs of ram.
For the desktop, you‘d ideally go full amd to not have to deal with the mess that is nvidias closed source trashcan drivers. Your games will be all over the place if you play, either they run better, the same or worse than on windows, very few dont work at all, quite a few require tinkering.
But all in all, if you are willing to learn, you‘ll find a distro for yourself. I recently put pop os on a fairly new gaming laptop and it works very well. Mint is the more non gaming variant imo, ubuntu is great for switchers but quite controversial, for more control but also quite a lot more tinkering, you can go debian, arch or gentoo. The last two I consider absolute tinkerers distros. There are hundreds more but thats for later.
Good luck and feel free to update on your progress or ask follow up questions.