Can I offset the metronome?

Thanks for the suggestions, @Rag and Bone and @SteveG_AudioMasters_ . I did (previously) just shift my music track along a bit, do the editing in time to the metronome, then shift it back into position afterwards - but thought "this is not ideal! There must be a way to shift the 'zero' time of the whole multitrack session!"....but I guess there isn't! I shall add a feature request along these lines.

Rag and Bone is essentially correct in principle, but I wouldn't do it like that... The problem is that the metronome doesn't actually put visible beats on its track, so there's no means to shift them - well not a simple one, anyway. There is a complicated way to do it, and that's to send the running metronome to an output on your sound device and then re-record it onto a different track. That will be visible of course, and you can reposition it where you want.

What is easier is to go to your Keyboard Preferences, and set something like the Z key to 'Select clips to end of session'. Put the cursor at the start, and now it's dead easy to pick up everything and shift it along. And if you get it wrong, you can  undo it and make the selection again. This is a slightly simpler (I think) method of what Rag and Bone is suggesting.

I don't know if you can...I can't find anything.

If no one with more knowledge answers:

Can you just add the necessary amount of silence to the top of the track to get it in sync? You can cut the silence when you finish the mix.