Congrats on your new camper.
The various PDI lists help a lot.
Take your time and read through the threads on this forum, too.
I look at the walk-through as both an inspection BEFORE I sign the final paperwork and a learning experience.
Is this your first trailer? If so, then you will want them to literally demonstrate everything from soup to nuts. Bring a paper and pencil for notes and maybe a video camera.
Most importantly, make friends with the service guys. You will be seeing them again and its good to be remembered.