Are there any RV Inspection services near you that you could contact before you go, to see if they could meet you at the dealer?
There are just too many things to look for, in the chassis and the coach, to list here that will give you any kind of fighting chance of not getting taken advantage of.
Do you have a friend that owns or has owned a motorhome? Any friends that are/were mechanics to have a look at the chassis?
Seriously, get the dealer to demonstrate every system in the coach to make sure every light, faucet, outlet, toilet, A/C, batteries, M/W, propane, oven, furnace, sink drains, and the list is endless, and that's just the coach. The chassis, check of rust/corrosion, old rubber belts/hoses, tire expiry dates, engine/transmission/differential/suspension/front end/dash gauges/mileage/odometer/dash controls/steering/brakes/etc.......
Not trying to discourage you, but if you truly are new to the RV/motorhome world, it's not like buying a car (well, yes it is, sort of, but there's a whole 12VDC/120VAC/propane/solar powered house w/running water and a toilet attached to it).
Get an RV inspector to go with you, or someone you trust that's owned or knows motorhomes and/or automotive stuff.
Sometimes the first MH you look at is the one, and sometimes it's better to pass it up and keep looking.
Trust your gut feeling, too. If it gives you a bad feeling after a few minutes, it might be worth taking a deep breath and sleeping on it. You've found one, and there will be countless others out there, if this one doesn't work for you.
Best I can do. Good luck.