Selling at school and got cought(please help me!!!)

So last Wednesday I sold a sack of weed to a girl after school right in front. The next day for some reason she brought it back to school and someone saw us in front and tipped the school administraiters so they called her down to the office and she gave it to a friend to hold and then she ended up snitching on her friend and then her friend gave it to her friend and the weed at the end of the day was passed on to 8 different people. All of the girls friends said she got it from me so I got expelled and I'm going to court. What do you think the judge will give me?