If it has been sitting outside without cover for three years, it probably needs:
1. fuel tank drained, and fresh gas
2. new tires
3. new batteries
4. fuel injection service
5. brakes and brake lines
6. house generator carb rebuild
7. fridge service
8. hot water heater service
9. water line service (potential frozen pipes)
10. fuel pump and ??????????
Before you do any of the above, give it a good washing and check for water intrusion inside. If you find signs that water has been leaking into the side walls, it is not worth fixing up.
If there are no leaks, and if you want to keep it, see if you can get a local mechanic to get it running. Once you know the costs to get the running gear sorted out, you can decide whether it is worth going further with it.
Bill
Coachhouse Platinum 232 XL