What now? Have my route mapped out...

Experience is the best teacher. I've logged well over 100k miles in motorhomes & I preplan everything as much as possible. Biggest concern for gassing up in a gas coach is maneuverability when towing a dinghy. You aren't, so you can back up. Look for the easiest lane to get in and out of - usually the outside - & not necessarily the shortest. Most important thing though is take your time. When driving. When gassing up. Take your time. And always, always get out & look for yourself and use a spotter to help direct you into places where anything could be hit. Enjoy this first trip & it will not be your last.