Hey so, incase anyone is interested (I know Habboi might be), I asked for help on adding detail to my map, and I did exactly that!
This is kind of what the area looked like at first: Then I took in advice to make custom textures, I made custom wall textures and grass, this is what that looked like: I still wanted more detail, so I added more props, and made a blend texture between a concrete pavement and the same grass, also tried CC: However I thought it was still lacking something, and that was atmosphere, I was using a bad sky, the lighting was meh, it wasn't that great, so then I made this: The end result.
I changed the sky and lighting, added fog, and put more detail into the surrounding areas. I think I did one hell of a job considering it was pretty much my first Source map (although I did make some really bad ones 3 years ago maybe? That doesn't count!) and my first time experimenting with all these new features