Zoom in & out
⌘ + plus/minus or ⌘ + mousewheelZoom in to see more details and zoom out to get a better overview.
Zoom - selection
⌘ + H“Zoom selection” is used when zooming in on a specific area of the audio.
Zoom -track height
Shift + ⌘ + Plus & Minus“Zoom Track Height” is used to make the tracks larger or smaller.