What should I change w/ my prison?

I’m not good at all with building things, and I’ve been trying to make a prison. The pictures below are my prison: (w/ future lighting)
!Screen Shot 2021-02-19 at 8.17.09 PM

Screen Shot 2021-02-19 at 8.24.04 PM|690x358
A few questions:

  1. For the inside should I change the texture from bricks to something like metal?
  2. Is there a good place to find textures to use?
  3. Should I change the roof texture to something else, and make the roof stick out a bit?
    Tell me what I should change. Also, if it’s bad (which it probably is), tell me, I would be happier to remake a prison rather then publishing a bad one.

Not sure why, but some of the files won’t load in this post. Here are the other two:

Screen Shot 2021-02-19 at 8.16.55 PM