First give it a wee shake, then the colored end a push. You might need to pump it 7 or 8 times to get it going. SO PATIENCE IS YOUR FRIEND. 

For the virgin user, try it out somewhere stable. Just till you get the hang of it-then feel free to take it anywhere. REALLY, ANYWHERE!

And get a feel for it-happy-streak-free nails come when there's a good amount of polish on the brush. So get a nice glob on there and start painting a few centimeters from the cuticle-so yah know, user your judgment.

Oh, and after if the bristles get a bit stiff wipe them down with a remover pad.