You have to be a bit more specific in order to help you.
You mention that you selected the Pointer Tool, but WHERE?
Piano Roll
If you are in the Piano Roll Editor, it should work right away.
Audio Track Editor
The Pencil Tool has only limited functionality. If you click on an empty space, it will actually open the Open Dialog to import an audio file.
Audio File Editor
If you are in the Audio Files Editor, then you should be careful because you are potentially perform a destructive edit. With the Pencil Tool you can draw in to overwrite the current waveform. However, this works only when you are zoomed in far enough to see the waveform line. The Pencil Tool becomes active and you can start to draw.
Fun fact: If you are not zoomed in far enough and try to use the Pencil Tool, it actually functions as a (temporary) Zoom Tool.
Hope that helps,
Edgar Rothermich
Graphically Enhanced Manuals (GEM)
www.LogicProGEM.com