Stop showing this pic of my shack!!! I didn’t send it to you for you to post it everywhere!!’
A “shed” or “shack”, with plywood flooring here in NC... prepare yourself for moisture. If you insult the walls and then decide to just use clear plastic to cover the insulation, prepare for sweating.
You’ll want to block the bottom up like a house or use underpinning of some type. If you don’t, it’ll be hard to keep warm in the winter. And in the summer, you better plan on having double the AC that any online calculator or HVAC guy tells you that you need.