Roadside Assistance Plan- such as Good Sam or AAA. I dropped AAA for Good Sam when we got our TT, better coverage for all our vehicles plus the TT.
Beware of Camping World, it causes credit card meltdown! J/K love that place, although Amazon is often cheaper.
Is it fair to assume a new unit comes with wheel chocks? We bought used and ours didn't. Harbor Freight has some nice ones cheap.
You may not need it for your maiden voyage, but I'd recommend getting a Water Bandit. It has saved us when we got a campsite with a stripped hose connection - at least we were able to fill our fresh tank since we couldn't hook up to the water full time.
You will probably want to get rolls of the anti slip matting to line your cabinets, Really helps keep stuff from sliding around while on the roll.
I also use the Camco fridge bars after the first time I opened the fridge and got attacked by the contents.
And I splurged and got the RV plastic hangers at C, World that grip your closet bar, too many trips where my clothes ended on the floor., now they stay put.
A power strip - outlets are never where you want them and so many electronics to keep charged.
All stuff you may want to consider eventually, not so much for the maiden voyage.
Good Luck and Happy travels.
2011 Rockwood Mini Lite 2304
2004 GMC Savana 2500
2013 Days Camped, since April: 33