I was a bit nervous since it's only my second year playing, but in my first year, I was named captain, and we won the league, so that built my confidence tons. Now, in my second year, I've been named captain yet again, so my confidence is there. I'm also on the All-Star team, and many of the players were on the team last year, and I'm new to this, so I was nervous. I made some friends and talked to them and figured out their style of play so I'm no longer that nervous.
It just takes time. And if you're scared to do tricks, then talk to your coach and see how he feels about it. Just don't overdo it.