I have flown into YNUB quite a few times,last time was was Ozkosh 2016. Avgas available out the back, PULP available from the bowser at the front.
Switch motor off at the side entry and drag plane to the bowser, when it is quiet enough to do so. You may have to wait while the campers and caravans fill up and move on. Borrow a milk crate from the fuel pay counter if you need to see into the wing tanks. Work quickly to get out quickly, some people don't register there is an aircraft at the bowser and just drive in behind you. Good if you have a mate with you to handle the curious ones while you get on with the refuelling.
You should have no problems, have a great flight.
Cheers
Rick