You might consider Linux Mint instead of Ubuntu. A lot of what you want is going to work (and be preinstalled) right out of the box. It’s a great system to start with.
I play Stellaris and Minecraft on Linux Mint… Stellaris runs fine through Steam. Minecraft, just download the Linux launcher, it will do everything else for you.
I’ve been a linux user for 25 years.
My computers are all named after Autobots and my wallpaper on each computer is a picture of that computer’s namesake from one of the various continuities.
That’s just how I roll out.