Most games are ok, big online games are usually not (anything that has kernel level anti cheat, straight up bans Linux, or uses a third party launcher that doesn't have much support on Linux). Usually can be overcome, but can result in a ban. For those games, you can either dual boot or virtualize Windows (which also can get u banned).

Tons of games have Proton support (check ProtonDB). If you select a stable distro and don't install custom stuff, you should be good without knowing much besides hitting Update all button from time to time and pasting any error message you get into your preferred search engine. Hell you can install SteamOS and be eternally happy.