Whizz-kid (informal) (2-6)

I believe the answer is:

go-getter

(Other definitions for go-getter that I've seen before include "Energetic achiever" , "Person who is successful by being aggressive and energetic" , "Enterprising person" , "One who succeeds through energy and drive" , "Informally, an agressive achiever" .)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.