Use polyethylene sheet membrane. Prior to concrete placing, cover the entire area with a layer of PE sheet membrane extending the perimeter of slab and up against wall for the depth of concrete.
It is a flat piece (slab) of concrete sitting on compacted soil or stone, usually meaning there is no basement. These generally only appear in areas where the ground does not freeze frequently.
I usually like 12" from dirt to the 1st wood Code requires AT the building a min of 6" If you will be adding mulch then you need to allow more clearance
The ground must then slope away from the...
It means water can get at the wooden structural elements setting on the foundation (as can insects)
You've got even more problems if you're some place here you get snow. The ground will be hard...