Unable to pull walls from 2D model

I am new to Sketchup Pro and am working on modeling my own living room. I created the 2D space plan, and now would like to create a 3D model. When I try to pull the walls up on the 2D model, I am unable to. Additionally, when I opened my file, the first “working” scene turned all black and I am not sure why. It was not like this about a week ago when I opened the file. I would appreciate any help/insights on these issues!
Z+E Living Room.skp (93.5 KB)

I just figured out the black problem. Somehow I had painted part of my floor plan black. Still unable to push/pull walls.

I have no problems pulling up the walls. See if you digg deep enough to be on the lowest level where you pull up the face instead of trying to pull up a group

Thank you, you are right. I was clicked into the group not into the object. That worked.