After you've banged up a couple of planes (the inevitable) and have been flying a while it will go away. Once you get to the point that you have confidence in your ability and concentrating on practicing precision maneuvers you will be thinking more about setting up your next move and less about being nervous. A plane is just some balsa, ply and covering that is almost always repairable and certainly replaceable.. Fly it and have fun. If you make a mistake don't worry thinking the guys are going to laugh at you. Every one of us has been there and done that (several times). Learn from it and don't do that next time. One of these days you'll be tellling a new guy the same thing.