When you pull in, if your tow vehicle fits you can keep it there. If you move it, you won't be able to bring it back there until camping is over. It would have to be parked in onsite camping parking which is just adjacent.
A pick up truck and a tent are not considered an rv and a tow vehicle. You may camp in your tent and park the pick up at onsite camping parking.
A van is not considered an RV and would have to be parked at onsite camping parking.