SketchUp Make 2017 won’t let me use the push pull tool because apparently it is not complete (i clearly have no idea how to explain this)
Push/Pull works on single faces. You don’t have many in that screen shot. Typical reasons for a lack of faces are gaps in the perimeter that need closing and a lack of planarity of the edges. It would be easy to diagnose the problem if you could share the SKP file.