You should be okay...as driver/owner of the vehicle, you are responsible for everything in the car even if your buddies are carrying it, but it's still a misdemeanor, so court fees and fines will prolly cost you about 150 bucks.

Ask the judge if he'll "Defer" the case, since you are a first time offender. This will eliminate the offense from your record after you finish a specified amount of time with no other offenses.