You have to transport people in this dangerous area. When you see someone with a sign hovering over him, stop by and pick him up. The destination place is visible on your minimap. For every ride you get some money. When you have enough money go to the garage where you can upgrade your car with plenty of weapons.
Steam Activation Guide
Activating a Product on Steam
1. Go to: http://store.steampowered.com/ and download STEAM client
2. Click "Install Steam" (from the upper right corner)
3. Install and start application, login with your Account name and Password (create one if you don't have).
4. Please follow these instructions to activate a new retail purchase on Steam:
- Launch Steam and log into your Steam account.
- Click the Games Menu.
- Choose Activate a Product on Steam...
- Follow the onscreen instructions to complete the process.
5. After successful code verification go to the "MY GAMES" tab and start downloading.