Am I in legal trouble or will this stay within the school?

You're a counterfeiter. Congratulations, I'm sure your mother must be very proud of you. You are in deep legal trouble. You've been stealing services and committing fraud. I imagine that you're going to have to pay a fine of a great deal more than what you used counterfeit tickets for. That's how it generally works, if you defraud someone, the fine is much more than repayment. You're probably looking at some community service or even jail time, too. This is a serious crime.