Sure, every club I have been to welcomed spectators. Some stages are more spectator friendly than others but you'll be able to see what's going on. I'd just shoot the match if I was you though, it's a lot more fun.
I'm pretty competitive ... I want to win, but I'm more or less racing against myself. I know my abilities, and if I execute them to what I'm capable of then that is all I expect and I will generally do well for the stage.