Salvaging is a great way to earn money when starting out. It's legal so you can do it in front of Gendarmerie and the resulting products can fetch a good price at Hardware Stores.
- Get a ToolKit in your backpack (there is both in your starting ammobox inside your house)
- Find wrecked vehicles (look in small + unstable yellow towns)
- Drive a vehicle and park it next to the wreck
- Use ACE-interact (Hold windows key) on the wreck and choose Salvage
- Items will be put into your vehicle (or the one closest to the wreck)
- Drive to a hardware store (tools icon on map)
- Park out front of the store and hit "Y" to Sell