You will get a few court papers in the mail. First one a preliminary hearing in front of a magistrate where you either plead guilty or not guilty. Second one you get is a notice to appear for an araignment at the court where they hand you your papers saying what charges. Last and most of all you get your actualy courtdate. So, Yes, your parents will see things in the mail from the state addressed to you.

If you plead guilty for that small of an amount, the worst I can see happening is 4 days in prison and a year or two of probation. Either way you will definately get probation and if they are going to try and get you for a DUI you will have a suspended license. That is worst-case and honestly not anything you will have to worry about.

Since this is your first offense, they will probably offer a program for you to complete where you will not go to jail but will be on probation with a suspended driver's license, and your marijuana offense will be wiped clean upon completion, however, IF they ring you up for a dui while high any DUI record will remain. No jail time, however. DO NOT FUCK UP AGAIN BEFORE THIS IS ALL SORTED OUT OR YOU WILL NOT BE OFFERED THIS PROGRAM AND THE CURRENT OFFER OF THE PROGRAM WILL BE REVOKED.

You really aren't in that much trouble. Get a public defender or lawyer to sort it out. In PA, they have a program called ARD where you can essentially lose your record for a first offense and I'm sure in NJ they have the same thing if not very similar. I fucked up and got another DUI before that case was finished and ended up in prison for a few days.

You will get a polic report mailed to you soon with all of the charges the officer is filing against you so it wont remain a mystery for much longer.

Either way you realistically have about 4-5 months before you have to go to court to be sentenced so you can sit easy and relax for a while and figure out what to do until that day comes.