Cannot edit a sound track[SOLVED]

I am new user. Installed Audacity 2.0.3 from the .exe installer.
I have opened a .WAV sound track.
The wave pattern shows up OK and I can listen and zoom in/out etc.
But I cannot edit the track.
If I select a part of the track and then go to the edit commands, all of them are grey (not working)
HELP!! What am I doing wrong?

You probably have playback paused rather than stopped. Try clicking the Stop button.

Thank you Steve! That was the key.