Make a good first impression and the judges will carry that picture with them as you are judged on everything else. Try to do at least two different jumps. Jumps are like everything else, it is not how many of them you do, it is how well you do them. Concentrate on good form and avoid all of the little errors that can add up to big deductions. If you do a herkie, try to do it on both sides.
All Cheerleaders can do a herkie on one leg or the other.
If you can show the judges a herkie on both legs you can get extra credit because they know how hard it is to learn it on both sides. If you do any tumbling try to keep it simple. A well done roundoff can sometimes get you a better score that a poorly done back handspring. Pick something you know you can do extremely well without making any mistakes and make it look good. Try to approach your tryouts with a positive, enthusiastic attitude.