As The Evil One said you just need to have someone who is 18 or older attend with you. You could ask an older cousin or friends with older siblings that are attending and ask them to be your guardian. Check around with classmates and see if you can tag along with them and use their guardian as yours. The best part of that is they are already going so it's not like you have to pay for another pass.
Best of luck to you in finding a guardian for SC!