Congratulation on the new MH and welcome to this group...
As far as the delivery process, found out and have the dealer demonstrate as many things as possible. Unless you ask, they tend to not offer any more than the basics. Have them run you through the water controls, heat and air condition, hot water heater and generator. Let them show you where each of the slide motors are and what to do if the stop working. Also show you where all fuse locations are. Walk you through the battery bay, identify where to add leveling jack ATF and battery cut off. And one they always don't show is opening the front engine cover and showing you the oil and transmission dip stick.
Don't let them control the time spent, this is the most attention you'll have from them in showing you things, so take advantage of it. Oh, did I forget to mention, don't sign the paperwork until after walk through.
Good Luck....
Steve