I want to ungroup the audio from the video on my timeline so I can edit them separately. When I select the video and press "u", nothing happens. When I right click the video, the "group" option does not appear. Does anyone know how I can ungroup the audio from the video?
Not exactly true. When items are grouped, selecting one selects all of them. So, selecting just the video or the audio is sufficient. In any case, when you have any item selected, pressing "u" dissolves the entire group it is contained within. Due to both of these reasons, there's no need to select both.
Still though, nothing visible should happen when pressing "u" or "g". It's what you do afterward that shows the difference.