Anyonw know how to get your HAND real STRONG and HARD really wanna know plz...DETALILS PLZ thanx (:?

Ok i used to live in california Tx where there i had many friends and we are all punks but it didnt matter in that skool...now im living somewhere else and i heard with the few friends i have rite now ): that a group of chiks want to beat the crap out of me the last day of skool just beacuse they dont like FREAKS but i have never fought before and i want to kno how can u make ur hand heavy and hard to defend myself too...i kno how to tell off real good...i always tell of my brothers but im scared theyll beat me up real bad...PLZ HELP ME!!! PLZ DONT BE RUDE THANX(: