Just play fun games at your skill level, and/or play with friends. It’s all about having fun. Don’t try to get into competitive games right from the start. Or if you feel like you can, join a team at your level.
Oh no, I never meant to get into it competitively. I don't get much joy out of that. But it'd be nice to have a PvP shooter I could screw around in every so often. CoD kind of used to be that for me, but it's both gone in a direction I don't enjoy and doesn't work well on Linux due to anti-cheat.
Try TF2! It's super fun and not competitive at all. Sure, its a little gimmicky but most of the players are in it for a good time and don't mind messing around a bit.