Nervous because you are inexperienced. When everyone has stage fright, after this game, you will have more confidence in the next game. I remember that people who like playing basketball are particularly flamboyant. You should make people pay attention to you, because you play well, and you should let your friends make the audience agree with you. There's nothing to be nervous about, just pretend that the people below don't exist. But I like people to watch, because there is no audience, games or movies have no meaning to play and play. Confidence, confidence, confidence.