Relax, if you've been a pretty good kid, doing okay (not great, just okay) in school, you'll get a lecture.
They'll send you to counseling and a class on honesty and one about not shoplifting, a few hours of community service, pay some fines (your mom and dad get to da that) let a few months pass, it's all over.
But, be smart. You can't keep stealing and keep your freedom.
So, stop, just stop and it'll all be washed away. You'll be pure and clean again.
Fortunately because of your age it doesn't matter that you are confused. You have no input in the situation at this point. Your parents and the court will work everything out. Your parents are the best source of information regarding your case.
You have no control over this as a minor. Your parents can hire a Lawyer to se what plea options are available to minimize the impact this will have on you and your family