1. Oil Change once a year
2. Generator Oil Change once a year
3. Waxing once a year, and cleaning materials
4. Winterizing materials if stored for Winter
Doesn't count all the small items you will encounter along the way. Just make sure you always have a small nest egg in case of anything major. Engine or Transmission etc.
It also depends what year model you are looking at.
Remember these things are expensive!
By the way, WELCOME TO THE FORUM and pull up a chair!