Let me add my best wishes on your new unit. 400 miles should be a nice little shakedown cruise. Lots to learn, just be patient and remember we are here and willing to help you through it. Everything is pretty much like your TT and Truck, just now its all together in one unit. Don't forget to inspect the burner on the fridge, it may have flakes of rust from inside the chimney blocking the openings and upsetting the flame, also go get a small one socket surge suppressor and unplug the fridge in the back and install the suppressor there. Cheap insurance against expensive electronic board repairs.
On the batteries, I have twin Interstate 12 volts. The 06 251 got a door and slide-out tray big enough for twin batteries and I added one. I think yours has just an access door, but you will need to service the battery before your trip.