What is the worst that could happen and how should I be prepared for this court case tomorrow?

Tomorrow morning I'm going to court as a witness to a thing that happened with some of my friends this evening. There was underage drinking involved, and one of my friends got very drunk, way too drunk. And so our other friend, who happens to be black, was trying to help him up and get him back home. But when he was standing over our other friend and trying to pull him to his feet, a man a few houses down saw this as our friend attacking our other friend. So he came out and started shouting at our friend and shoved him. Our friend defended himself by pushing back, and the man started shouting to the street that he'd been assaulted and for someone to call 911. Me and my other girl friend tried explaining to the man that there was a misunderstanding and that we were all just trying to get home. We tried to get away from the man, all of us, but he continued to follow us and continued shouting at our friend and pushing him and yelling for 911 to be called. Me and my girl friend decided it would be best for us to try to get out of there, because our two guy friends were continuing to be shoved around by this man and were defending themselves. The cops showed up, and apparently our black friend was arrested (I include his skin color because personally I'm certain the guy who attacked us was making a racist assumption about the situation), and all three men are currently being detained. Me and my other girl friend are supposed to show up at witnesses to the court case tomorrow morning, and being that I've never ever ever been involved in something like this in my life, I really don't know how to handle it or be prepared or anything whatsoever. So I guess I'm just looking for counseling of some form and any input on what's the worst that could happen and how I should be prepared? Thank you.