To select a single track, click its Track header in the Track list. You can also click an empty area in the Content view. When you select a track, Timeline highlights its Track header and Content view. Selecting a track deselects all other tracks or clips.
Selecting a track also shows its properties in the Inspector window. The track properties change depending on the type of track and how many tracks you select.
To select contiguous tracks, select the first track and then hold Shift and click the last track in the series. For example, to select three contiguous tracks, click the first track, then hold Shift and click the third track. All three tracks are selected.
Click to select the first track
Hold Shift and click to select contiguous tracks
Hold Control (MacOS: Command) and click to select discontiguous tracks. Hold Control (MacOS: Command) and click to deselect a selected track.
There are many other ways to select tracks: