During the building of my tune, some of the tracks ended up before “time zero” - Audacity automatically corrected latency in my recording. So, I ended up giving myself some room to play around with as I built the rest of the tracks. That said, now I need to remove a couple of seconds from each track.
The easiest way is if you shift all of the tracks together to the right so that you can see the start of each track.
To do that, Ctrl+A (select All)
then with the Time Shift tool, drag the tracks to the right a bit (does not matter if you move them a bit too far, as long as you can see the start).
Now to delete the start from all tracks:
Select the part that you want to delete in one track.
Then press Ctrl+shift+k to extend the selection to all tracks (“Edit > Select > In all tracks”)
Then extend the selection to time = 0.0 with Shift+Home key
Then press the Del key to delete.