I’m mixing different tracks, of differing lengths. How do I get my shorter tracks to start where I want them to? Everything starts at the beginning–but of course, that’s not where I want it to be in my mix. Thank you.
Press F5 then click and drag. See Time Shift Tool .
If you are mixing this down to an exported file and you want the space before the audio starts to be preserved, click just after time zero in one of the tracks that does not have audio starting at zero, then hold SHIFT and press HOME to select from the click point to time zero, then Generate > Silence.
If you are using File > Export Multiple to export each track as a separate file and want the space before the audio to be preserved, generate silence at the starts (as above) for all tracks that have space before the audio.
Gale
Thank you very much.
And afterwards don’t forget to click F1 to get the normal selection tool back 
WC