This is an important lesson. The lesson is - dont say anything to the cops no matter what. The cops act "cool" so they can get you to say what they want you to say. Ever heard of "good cop, bad cop"? They write down every little thing you say in the police report and it "can and will be used against you in a court of law" - hence the expression. I know this from experience - my brother learned the hard way b/c he didnt know to shut his mouth. You are still young and the charge is probably just a slap on the wrist but now you know for the future. The police are not the friends of weed smokers. Peace.