Here's the blocks being dug into the ground to where they're all level. My compacting work seemed to do well, it was hard as heck to dig down a few inches by hand. Our soil here is sandy, so it wasn't due to clay, lol.
Per the manufacturer's recommendation, I put down 4x4's. I could only find 8' ones that weren't twisted to heck, so I doubled them up like this.
Here's the floor in place. The kit came with an 8x10 floor kit and a 4x10 floor kit extension. The long pieces from the kit were supposed to be made from 4' and 6' pieces. I bought four 10' 2x4's and replaced them. Something to keep in mind, the treated pieces that come with the kit are 3 3/8" instead of 3 1/2" wide. It worked for me because the long 2x4's aren't resting on the 4x4's, so they just hang down a bit further. If I knew this before, I would have cut them to the same width.
One advantage of doing this is the extra pieces left gave me enough to make the floor joists 12" OC instead of 16" OC. I would recommend the same for anyone who gets one of these kits. I bolted the two floor "kits" together before the OSB went on.
I know the picture puts things at a funny angle, but it's square and level.
The last picture makes it look like I didn't get anything done, lol. I have an awesome neighbor that came over to help me for a good chunk of the weekend. Using a nailgun and no-drill screws makes things go much quicker. Unpacking and sorting this kit by itself is quite a bit of work. We got the four main walls framed, racked, and sided (the kit comes with pre-cut combo OSB/siding panels that you put on while building each wall to rack the wall.
I also replaced the top and bottom 2x4 pieces of the end walls with continuous 10' 2x4's intead of the 6' and 4' pieces.
At the end of the day, we stacked everything onto the floor and tarped it for the rain this week.