Skiddable structures are great, you can drag 'em just about anywhere. Now you got it there, you need to level it. Rocks to the rescue! Build a level "foundation" under your skiddable structure, to both level it and slow rotting of the skids.
To get certified for this BB, do and post the following pics:
-Show image(s) of the shed before work
-Show image(s) of leveled shed