Communicate with Gruppe Leader, Forward Air Controllers, your Wingman, etc.
Keep yourself and your wingman alive and get into position to kill the enemy.
In most situations, the Flight Leader will be the shooter when engaging the enemy.
(2) Flight Leader's Wingman Responsibilities:
Follow the Flight Leader.
Your job is primarily defensive. Keep your Flight Leader's tail clear. Avoid the desire to break formation and engage enemy aircraft. That's not your job. Let the Flight leader focus on killing.
Stay off the radio unless you have a 6 call, a bandit sighting, a technical problem, answering queries from the Flight Leader, or something else that is important to the combat situation.