There is a book titled Off to a Flying Start: Horsing Around the Language. What does off to mean?
I did some research on it and I feel it means going to do, but I still need your confirmation.
See a few examples below.
It can have several meanings. Most of the time, it means you're going to (not going to do). In the first sentence I'm off to Canada next week, you're going to Canada the following week. In the second, you're leaving where ever you are to proceed to do your homework.
It has more of a informal atmosphere a large percentage of the time and is used in conversational talk mostly. If you're having a talk with somebody and you want to end the conversation, you may say "Well, I'm off to take the kids to school" instead of "I'm going to go and take the kids to school."
Another usage of the phrase off to can be seen below.
These sentences use off to as "beginning with" and, for example, the first sentence's off to can be replaced with "I'm beginning with a good start, but ..."