Welcome and congrats!
Write everything down or videotape their demonstrations to watch again later.
Test everything, actually everything.
Make a punch list of things to be fixed and make the dealer sign off on it. Some dealers don't like to do this because they can't "book" the sale until all "deliverables" are completed (financial accounting rules). Just tell them that's their problem not yours, and the sooner they fix the list the sooner they can "book" the sale. Be prepared to play hardball if needed. This is the day (the one and only day) you have maximum leverage.
Be sure they give you a complete set of manuals. That should be at least 4-6" of manuals and it should include microwave, oven, furnace, thermostat, radio, air conditioner, water pump, slide units, alarms, toilet, water heater, basically everything you can turn on and off, everything electric and everything plumbing. If not, get them to commit to providing you those.
Ask and try to see if they have and can give you a list of the appliance model numbers and serial numbers. I seem to be the only one in Forest River land who got one of those, and it's has been great for looking things up.
Also be sure to get the chassis manual, i.e., Ford, Chevy, Mercedes Benz whatever it is. Should include an owner's manual, a maintenance manual, and often a separate 'how to use the electronics' manual.
Hopefully they will give you a "starter kit" which generally includes at least a sewer hose, toilet paper and a fresh water hose, usually in a useful 5 gal. bucket. If not and if your unit doesn't have all those things, you will need them before you can even use the unit. Starter kits may be available from the dealer but Camping World has them too.
Generally it's advisable to camp a night or two at home or near home to give everything a shakedown test and realize what you don't know how to do yet. Also run the furnace for a good solid hour with all the windows and the door open and vent fans on. You need to burn off the oil from the metals, and these fumes are really smelly. You won't want to be in the unit during this first hour, and you need to get it done before you go camping.
Good luck and have fun!
2016 FR Forester 2401R
Towing 2014 Honda CR-V