You can drive it if it's street legal. Otherwise you can flat tow one vehicle to the park. If you have more than more one vehicle to bring inside, put the other in the bed of the truck or bring in your cargo trailer.
If it's a weekend you will need a parking lot voucher for the trailer, or a dune ready voucher for the truck/towed vehicle combo. Aside from a stop at the bathroom, you cannot use the parking lot to park your vehicle without a parking lot voucher.
Regarding ATV at campsite, each campground is different so check with them. No revving the engine. It will get you kicked out. ;)