- Make sure you have Video and Audio on separate tracks (File>Settings>Program, Video/Audio tab, untick "Video/Audio on one track".
-On the audio track, wave the mouse over the track and a fader ball will appear at each end. If you can't see it, zoom in a bit. Drag the ball inward to set up the fade.
The handles only show up when you move the mouse over the object. Also, the object has to be large enough on the timeline to be able to display the handles.
An alternative way to add fades is to select the object, Shift+N to open the trimmer and do it there.