What Can I Do to Myself To make me Cool?

All In High School i have been an outcast and it only struck me today that I don't have any friends. All I want to do is to be cool, just to find a few friends and hang out with them at lunch and recess. What do I do? Do I change my Look? Do I change my voice ( as in speak up and more often)?. Please, what do I do?, i just wanna make friends and be cool.