How can I be a cool Freshman?

Okay I'm a freshman now and I need tips on how to act and not get made fun of right when walking through the door. I'm not baby acting or preppy, or even "Ewww you smell bad" middle schooler. I was jsut wounderin what I should act like, and your opinion if others will except me rather than hate me... Well I'm an explorer firefighter (meaning actually going to accidents and fires and working with the fulltimers and volunteers there) and I'm on my forth year of being a guitarist and I'm in a band. I'm a major down and dirty tomboy and I dress kinda dark like. (meaning baggy camo pants with a Billabong shirt and skateboard in hand) Now please don't post comments that won't help...