Renting out my mobile home that's on a family member's property

[Layci Smyth]

I live in FL. I own a mobile home, that I inherited from my mother. It's on my Grandfather's property (no issues there), but my Grandfather's wife's son (not my real grandmother), stays there. From what I understand, her son paid enough money to cover lawn and pool expenses and that's it. My mom didn't make a dime but she didn't need the money either. I want to make a lease agreement for a decent amount of rent, to cover my costs of major repairs just in case, and pay my Papa a couple hundred for lot rent so he can cover property taxes. Its a 4bedroom/2bathroom doublewide, with an attached front and back porch, and an inground pool. I am being fought tooth and nail by my papa's wife and her son that it is not worth paying $800 a month for and nor will her son pay it and I can't just 'do what I want'. Can someone please enlighten me on anything they've experienced with what can and cannot be done by me as the homeowner, but not the property owner.