We didn't have many things we needed for a long trip that we didn't already have for a short trip. Some things we had to consider for our first long trip after retirement (three years ago):
1. Mail delivery
2. How to pay bills
3. How to renew vehicle registrations
4. Where to get medications on the road.
5. What to do if you get sick on the road.
Think through all the scenarios that can occur and plan for them. Unfortunately, we were on a long trip this last summer when our truck caught on fire. The blaze spread to the fifth wheel and destroyed it too. We lost nearly Everything! Whether you're on a long trip or short trip, we found out it was a good idea to have a "bug out bag" that was easily accessible in an emergency. It should have your important papers, credit cards, jackets, laptop, phone chargers, etc. It would have made our life much easier if we'd had it. We've since replaced everything and we're better prepared for an emergency on the road now. Our motto is prepare for the worst and hope it never happens.
Jim