Hi there! I’m so proud of a student of mine who mastered the use of the expression “Off we go”, kind of (kinda) difficult to understand, that we saw in class!!
“Off we go…” Means that you are leaving to go somewhere.
She could have said “Off we go!” or “Off we go to New Zealand!”
It is usually used right when you are actually setting off (starting to go somewhere, moving). An example would be like you’re in the car and someone presses on the accelerator and says, “Off we go!”