"Action, Go!" ... is as much as: Let's go! This song shows the development of the performer, who was insecure and rather shy at the beginning of her personal development, towards the joyful, self-confident JUST Mandy.
It's a wake-up call to leave one's comfort zone. To have the courage to dare to do things that have never been thought possible, and thus to take life to a higher level. It's time to take off!
JUST Mandy is leading by example.
ACTION, GO!