Woo Ha!!
To move about excitedly as if dancing to Caribbean folk music.
Apollo Creed was the opponent to Rocky in both Rocky I & II. He was the heavyweight champ. Busta is saying that he will knock you out like the great Apollo Creed.
Busta Rhymes is declaring that he's the Top Gun (the best) which is the name of a Tom Cruise movie. He will then metaphorically "shut down your firm" (destroy you). The Firm was also a Tom Cruise movie, where he shut down a corrupt law firm.