new to diesel

Be sure to get a Pilot/FJ RV card. This will allow you to start the pumps at the pump so you don't have to go inside first. Once you are done pumping you move the RV forward and then go inside an pay. Every now and then I can find a station that's not a truck stop where there is easy access but in general I use truck stops to ensure easy in/out and no chance of damaging anything.
I also use the Gas Buddy app to determine when and where to fuel as one city/state can have substantially higher/lower fuel pricing and the large fuel tanks allows you some flexibility.