Starting a coop and would like input if you see something wrong

Oh, you can also use some tin or corrugated iron roofing or fencing or wood to make the skirt for the bottom few feet of the coop.

That picture inside a hollow wall? That's a strange looking picture!

You might want to think about whether to use a solid material for skirting or not. With the heat that most of the country has been having solid material at chicken-level might be counter-productive in that it will stifle most of the breezes that they might could have got.

A 1/2" mesh wire or smaller would be great around the lower perimeter, though. As GP mentioned, there can be a problem with chickens reaching through the large gauge fencing.

EDIT: Ok, I just looked at your last picture and saw where you had used chicken wire.. Chicken wire will keep the chickens inside the pen, but it won't keep predators out. Raccoons and dogs can tear through it fairly easy. I would put some 2x4 welded wire over the poultry wire, if nothing else but around the lower portion of the pen...over the entire pen would be better, but at least at the bottom you would take care of most dog attacks. If you can't handle the cost at the moment then maybe you work on acquiring the 2x4 wire in the future.

Best wishes,
Ed