Everyone starts with one contact (bonus contacts for those with high Charisma scores). This is basically a person who is always considered friendly toward you (within reason) and can help you with favors within their ability. Of course they may ask for help in return and the bigger the favor the more dangerous the return favors may be.
If you're new to the city, you could still have a contact in town. Someone you came here to get in touch with. Maybe they invited you to stay with them until you could get on your feet. Or if you're a foreigner, you could have a contact in the embassy. Or maybe someone moved here with you, etc.
This is something you can detail as much as you want or leave vague and I can fill in the details. It's mostly for role-play and a way to get your character tied into the city. And in case you're wondering there will be plenty of action, too!