I'm assuming the open container was in a motor vehicle that you were driving or were a passenger. I doubt if this is a misdemeanor, but more likely an "infraction" which means you don't get sent to jail or have a jury trial.  If it is a misdemeanor, however, ask that the charge be reduced to an infraction.  But if it's a vehicle code offense, it could result in points on your record as  "moving violation," which the insurance companies may hold against you. If you can go to traffic school, I suggest you do that.  Any offense involving alcohol  in an automobile can have unexpected collateral consequences--higher premiums or insurance cancellation. You might even want to bring up why you were stopped in the first place because it could be an "illegal search and seizure." But that's a Fourth Amendment problem and can get complicated.

I hope this information is helpful to you.