Walk In The Park is the first mission available to you in the game. That said, it is quite simple. If you complete this mission, you will gain access to the DedSec Mission Select screen in the DedSec App. To begin, simply exit the headquarters. As you exit, walk forward into the park. Your crew will contact you, imploring you to utilize your net hack mechanic. Use this to scan the area for a potential side operation. Look to your left and you will see someone you can talk to. Walk up to the man to begin the side mission: A High Price to Pay.