Ok, so you use the meshes from the starter conten? -> click on on the wall - right click - find in content browser - now it should select a mesh in the content browser (when there is no “find in content browser” it’s a bsp). Post the name of it into this thread so that I can check it 
bsp = the geometry tool. In-editor “mesh” creator
mesh = object made in a 3d program (or converted from a bsp)
uv map = you have to change that in your 3d program so that the texture gets displayed correctly (but I think you just use the starter content -> so atm you dont have to do that)
I think that’s how you want it to look like?
