Sign up for a tournament. Be sure to practice every day leading up to it, possibly at the same courts that the tournament will be played on. The night before, go to sleep earlier than you usually do. You might have an early morning match or an afternoon match so set your alarm clock to the appropriate time.
In the morning when you get up, have a good breakfast, such as eggs and Post Raisin Bran, or oatmeal pancakes. This will give you energy for a good part of the day. Get ready for your match. Dress in your most comfortable tennis outfit, and tennis shoes. Apply a lot of sunscreen if it is sunny out and you are playing outside. Before you go out to play, have a banana about thirty minutes before you play, so you can have a lot of energy for the match.