Get plenty of tea towels. Not just for the obvious but they are useful for putting in draws and cupboards to stop pots, pans and cutlery rattling about when driving (really annoying)
Also get some peppermint oil and cotton wool balls. When we put our van in storage for the first winter we had the van, mice got in. Second winter we soaked wool in peppermint oil and no mice. They hate the smell. Our mates van which is parked next to us got the brunt of mice as they didn’t do this trick.
Also remember to get some air tight storage boxes for winter storage. Don’t leave anything in cupboards whilst storing. Put them in the boxes as mice will use stuff left in cupboards as beds. If empty they won’t bother (although if you do the peppermint trick it shouldn’t matter)
Nitrile gloves for when you’re emptying the toilet.
Skin so Soft is a life saver to keep midges away in Scotland. Never leave home without it.
Get a tow rope. We have needed it at festivals and when our clutch pedal broke. Tenner from Halfords or ebay.
Safety is number one priority-Hi viz jackets(one per passenger) Warning triangle (at least one) First aid kit,fire extinguishers,torch. Breakdown club card and spare wheel.
Non-slip matting for the cupboards. I bought a new dinner set (from B&M Bargains,nothing posh) and used the cardboard packaging that came with it to slip between the plates, bowls etc to stop the rattles.