If it's you're first offense, you'll probably get a slap on the wrist, especially if you agree to pay damages. Depending on the judge, you could also spend a couple of nights in jail(real jail, not juvie or house arrest) to put the fear of God into you so you don't do monumentally stupid things like that again. You realize someone could have gotten killed, right? Granted that's worst case, but depending on the driver and traffic conditions you could've caused a wreck.
My suggestion, work out a plea to a lesser charge. The judge would probably look more kindly on a kid who, realizing what he had done, owns up and takes responibility like an adult.
