Have the Dealer put water in the clean water tank, while you are watching him and see how that works, over flow, lights on console, water pump, etc.
Make sure all faucets and toilet and shower works ok.
Get a lug wrench at the Dealer and make sure it works/fits... I have a 'fat' lug wrench from my old camper (did not work on new camper) and the lugs/rims need a 'slim' sided lug wrench. After 50 or so miles, stop and check all the tires lugs. Don't have to 'torque' them yet.... but 'torque' them when you get home.
2013 Forest River Salem Hemisphere SBT312QBUD
2001 CrewCab F-250 7.3 PowerStroke Diesel
SuperChip, BTS transmission, 6.0 Trans Cooler