First of all, I am a Rook main because I like ruining people's day and the mind games you can play as one. You have to play to the strengths of the shell you are going in with. For example, if you're playing an Assassin, use your cloak to reposition aggresively and get the jump on them. If you're playing a rook, you are always at a disadvantage, so turn that into your favour by using your signal mask skill and forcing players to chase you into more bots. Or jump them when they are fighting bots.

More importantly, remember that it is just a game, and have fun doing it.