Congrats on the new bus, I can see you grinning from here.
May I suggest a good tire gauge is probably the number one tool if I had to pick one, and an inventory of all engine/generator/alternator/a/c belts. Both metric and SAE wrenches have been required on the coaches I have owned, plus someone always wants to borrow one.
I am sure there are others who have worthwhile recomendations.
May you have as much fun and pleasure from your new coach as we have had with ours.
Roger that!
2008 Liberty DS XL2
2023 Denali Ultimate
My 6th Prevost