A. Let’s clarify. The kitchen is a non-Volley Zone and it is a more accurate name for the kitchen, so from now on we will refer to the kitchen as the non-Volley Zone (NVZ).
As always, the ball must bounce on your side before you can step into the NVZ. You must get out of the NVZ before you can hit the next ball.
The answer to the question above: This is a foot fault.
From the rulebook: 9. D. If a player has touched the non-volley zone for any reason, that player cannot volley a return until both feet have made contact with the playing surface completely outside the non-volley zone. A maneuver such as standing within the non-volley zone, jumping up to hit a volley, and then landing outside the non-volley zone is prohibited.