When you get it ask the dealer for a quart of oil; if they won’t throw that in buy one as you set out.
Take a couple of simple tools - screwdrivers and wrenches in case there is some fixable failure.
Cell phone and charger for the drive, probably obvious.
Since you drive, you probably know the routes. I prefer the northern route this time of year. Too bad the wife isn’t along or you could visit several nice places (Yellowstone comes to mind). But since you’re power driving, the northern route has some faster interstates.
Don’t run the gas too low, you want to keep good gas in it and not be sucking any condensation.
Do a visual and running inspection of the cooling system to be sure it is full and not leaking. No cracks in the reservoir, etc. If there is anything problematic, replace before starting out. Hopefully the PPI already gave you comfort here.
Make sure the washers work front and rear, the fluid is full, and all wiper blades are in very good condition.
Relax and have fun.

__________________
Mike

2005 e53 X5 4.8is 169k miles
2018 f90 M5
2018 Volvo XC60