What is the best thing to do in a street fight?

i live in a bad naborhood (middletown ny if you wondering) and every day ther semes to be a fight. now iv never ben in a fight but just incase i do im not shure what to do. im not trying to look for fights. but ive got a fue good enemies that i know of. for starters what is a god stance.second is ther anything i could do to stop ther movment or weken ther mussles.what parts of my body should i prevent them from hitting so im safer.