Welcome from another Mark & Chris
Good idea on the local camping stop before you get too far from your dealer. The PDI and walkthrough are key as well as the dealers prep before you get there. Our dealer was talking about how thorough their prep was and we got into a little joking bet on if I could find an issue. They did their job well but I still found an item. On the walkthrough as this is your first 5th wheel, take lots of notes. Make sure you understand everything and know where all the switches, controls, valves, etc are. Also check to see if they have sanitized the tank or if you need to do that. Main item is to have fun and enjoy both new rigs