Teflon and microplastics battling it out

You can use sand to help level out the cement blocks. Just get the measurements between the 4x4s on the bottom to make sure the blocks are spaced correctly. Use a 2x4 and lay it across the blocks to see which ones need to be raised or lowered etc. It's really not too hard, took me an hour to set mine up

That's exactly what I did for my 10x12 shed. Worked great and holding up very well