How much trouble would a fistfight get me into? i'm in my freshman year of high school...?

i have been picked on for three years by the same group of *ssholes and now i have to go to high school with them. everyone tells me that high schoool will have more freedom for me and less teachers riding my *ss for no reason. if that is true for me, then it is also true for all of the freshmen. and if there's one thing i know about bullies, it is that they flourish with little or no adult supervision. i've already decided not to take their crap this year so don't tell me not to fistfight. i'm done with nonviolent solutions. if they run up to me slap me in the side of the head and call me f*ggot, and i throw a punch at them, and maybe even knock them out if they don't run away like a b*tch (i'm not a weakling) how much trouble could i get in? would i get expelled the first time, or is it like a three strikes thing? will this follow me around for the rest of my life? i don't want to miss out on yale because i beat an *sshole up, but i do want this to stop.