Shed Floor Idea

Ok, so I had a junkie awning and no shed. I had an idea in my mind of how I could use it.
One day we tore the old awning that I was going to use for the shed roof construction down. It was a weird structure that was built upside down. The framework was on top. Later a friend revealed to me that it looked like the old metal stripping that used they used to make trailers for semis.

A week later, we pulled the decking boards off of the deck. It was about ten by ten, and the floor joists were made from 2 X 12 lumber.

My wife and I dragged the deck joists in one piece about 30 feet across the yard. Actually, now that I remember, we rolled it to the shed site end over end.

I had in my possession free floor joists, a roof and old cedar siding from a commercial building. As I began to piece it together, I wished I had a plan. In my mind I saw plywood decking on the joists, 2 X 4 studs for walls and my old used awning laying frame down on top. I learned that there was more to it than I figured on.
A plan with all the elements laid out and the order of progress would have been nice. My advice is that if you are going to build anything, get a plan even for a shed.