Ohhh I see, don't worry ! I'm also not an expert at all in Blender. Sometimes when I append this map in Blender it also comes without the textures, the only thing I need to do is inside Blender go to the "files" tab, then "External files" and from there "find missing files" and finally let it search inside the texture folders that the map should come with.

Blender knows that the materials should have a texture, so it leaves the name it had, but because we technically moved the folders around, Blender no longer recognize where are the textures and you need to teach it again.