No matter what, there should be chains. If not, have the seller address that now, before you get there.
You also need to check the wiring on your tow vehicle to see if it accepts the type of electrical plug that will be on the camper. You didn't mention what year the Coachmen is, but chances are it is a 7-way or seven blade connector. You will need to have the same thing on your vehicle or at least the flat 4 connector and an adapter to the PUP's 7-way.
Check over the tires, as trailer tires outlive their useful life often long before they run out of tread. Look for any cracking in the sidewalls or wear patterns such as no tread on the inside edge.
There's a whole host of other things (we didn't even go into brakes and a brake controller for your tow vehicle) but just be safe and enjoy the new PUP. We have lots of great memories from using ours.
