How are they not showing up. On the timeline? In the project media? On the hard drive where they were captured to? If you captured to an external drive is it still available to the computer?
Chances are you have kind of shoved it off the screen somewhere. Try increasing your screen settings (makes everything smaller) and see if you see it to one side or the other. If so drag it back to the center and resize back to normal.
I am not at my editing box right now so I can’t tell you exactly where but there is a setting somewhere that controls what you see on the time line from nothing (like it sounds like you have) to continuous updated frames.
Volume envelopes arebonly available in the full Pro version. If that is what you have go to insert envelope audio volume. Then there will be a line in the event that you can add nodes to and adjust different areas to different volumes.