All this stuff may be in other posts, but . . .
Unless you enjoy a Diesel Fuel Aroma, get rubber gloves to avoid the diesel stink on your hands, and keep them in a convenient storage locker in a bucket or bag. Auto parts places and truck stops all have them.
Watch where you walk around the diesel pumps. Frequent spills track into your RV and stink and stain your carpet. We carry a piece of old carpet to wipe our shoes on, and remove them after fueling till we get someplace to walk in a gravel or dirt area and scuff it off.
Our RV (Winnebago) is hard to fuel with the Semi nozzles, they are too big to fit in the tank opening so you have to stand there and hold the nozzle for the whole fill. PIA! Many stations have RV pumps, made for easy pull-thru.
Arizona charges more at the diesel pump in the semi fueling area than at the RV pump.