Consider shipping some of your camping items to Tucson. Check brakes including trailer brakes. Plan on having to use back in sites not just pull throughs. Find a empty parking lot and practice. Walmart has cheap hand held radios that might be useful including use in large stores.
25K miles on a 08 truck would make me suspicious with all of the flooded vehicles on the market but that is a boss problem. Ditto for the TT.
Major checks before you purchase the trailer include chassis rust (salt) and water damage - ie soft spots. Maybe hire a professional as unseen repairs can be costly.