If your school does Freshman Friday (where freshmen get beat up) the best thing is to inform the pricinpcal of such an event. They really wont take kindly to this. Also make friends who aren't freshmen, so they can back you up. Another great thing to do is bring an apple and a blade with you. When you see seniors looking to beat you, pull out your blade and apple, cut at the apple's skin and eat, it makes you seem innocent but also advertises that you have a blade so they dont forget with you