You didn't mention anything about a workshop, or a place to build stuff. To me, it sounds like you want a building to park all of your stuff and keep it out of the weather. Then you are thinking of creating a small house on top of this building just in case somebody comes to visit or stay with you.
In my opinion, it's a massive waste of money to build for the unknown. What if you build it and they actually show up and want to use it? I want visitors to leave as soon as possible. Long stays are never welcome. I could spend the money into making them comfortable on a lot of other things, including their hotel if I really wanted them to visit, and not have to deal with maintaining an empty space after spending a lot of money creating that empty space.
A loafing shed is basically a long building with one wall open for getting into the building. It's very common for livestock and hay storage. It's also very common for tractors and implements. If there is no other reason to spend a lot of extra money, then all you need is 3 walls and a roof. You can add garage doors to it later if you want, or just leave it open.