the actual SteamOS is probaby not a good system to use for your PC. I would suggest using a distro that focus on gaming. The SteamOS is focused on the SteamDeck
Check out this page for a good list of gaming distros. https://distro.watch/distros/category/gaming
I turned my friend onto Pop and he used it for a bit and then went to something else but he has stayed on Linux so I consider that a great win and a good starting distro for a newbie. It has good nvidia support out of the box.
I use arch and have built it from the ground up, but I would not recommend that to a newbie. But if you get confident with linux and want to maximize your potential, arch is the way to do it