If possible video tape the PDI or at least parts of it. Make notes. If you are uncomfortable with anything that's the time to ask, especially if it's something on the trailer that doesn't look right. Any good dealer will make it right on the spot. Good dealers will also leave the door open to call with questions about things you still don't understand.
After you take it home, do a two night weekend at some RV park within an hour or so of home. You'll get a chance to test everything out in the "real world of RVing" and you'll come up with a good "needs and wants" list.
2013 Jayco Jayfeather X20 E (sold)
2016 Chevy Silverado LTZ 2 Z71 Crew Cab (sold, and dearly missed)