Now im not ganna put my whole story here but basically if this other kids parents want to press charges i get charged with assault and battery.
i am a minor(under 18) and i live in the state of California
so my question is that if they DO press charges how fucked will i be if at all(this is the first time i have been charge with this and i have not had any trouble with the police before).

most likely slap on the wrist...do some community service, probation..if they decide to look at you as an adult than than same thing considering you have no criminal backround.. Most states have a surpervision thing where if you stay out of trouble for 6 months then they will drop the case..most likely you will get that

Do you have any priors? If they do decide to press charges I would definitely lawyer up regardless. With a clean record you could definitely get the charges dropped to something less sever and end up with community service

Was this a fight or an attack? If it was a fight, your offense is mitigated by the fact that it was mutual combat, as long as you didn't go to far. If you attacked him maliciously, especially if you clearly outmatch him, you're probably screwed.