Replying to WHAT DO I DO!!

i need some advise on what to do, tonight i got pulled over for going 91 on the way from boreal and my parents are a tad pissed and they say that i cant go anywhere but school and my fire station (im an ROP student). i have my girlfriends prom coming up on the 5th and she already paid for me to get in because she goes to a different school than me since shees loaded. but basically im not sure how i can swing getting out of groundation for sat night/sunday morning and i wasnt planing on telling my parents that im going to her prom since my mom is Jehovahs Witness and wouldnt let me go anyway. so i need a plan for next sat night/sunday morning