We have no clue where you are so we can’t give any good advice. For all we know you live in Elbonia and driving without a license gets you the guillotine.
But
Show up ~30 minutes early, there will likely be metal detectors and a line at them. If you are in line be ready when you get up front, if you need to empty your pockets do that before you are at the detector. This makes it faster for everyone.
Showing up early will also give you time to find your courtroom in the building. It also will let you watch the court for a few minutes before your time to shine.
Turn your phone off. Court house rules might require you leave it outside.
Dress appropriately, a polo should be fine. Any collared shirt tucked in with pants and closed toed shoes will show you put some effort into dressing yourself. No hats unless you’ve got to for your religion.
It’s the judge’s courtroom don’t interrupt them. Don’t lie. And being on your best behavior starts the moment you step onto the lot not when you enter the room, be polite to court staff as well.
Read the ticket front and back for specific instructions. Check the court website to see if there’s any announcements that you should be aware of (like local rules).
Don’t listen to other people’s advice on how you should plead. We don’t know the facts of your case. Most people here aren’t lawyers. Nothing here is legal advice.
“the US” doesn’t narrow it down much. I kinda assumed that much. What really matters if which one of the 50+ legal systems in the US he is subject to. And which courthouse he is going to.
This is going to 100% be a state law matter, unless he lives somewhere like D.C. or Puerto Rico which aren’t states but fall under federal jurisdiction.