You need to complete 100 different deliveries in total. (10 for this achievement but you need 100 for another achievement) There’s 100 deliveries but with the DLC there’s 130. You don’t need gold but if you get 50 gold you unlock the UFO at your garage. The UFO makes deliveries even easier since it’s simple to fly, you can’t crash and you can easily carry packages in it. You can check how many you did in the pause menu under deliveries. Completing a delivery in a co/op game counts and adds to everyone’s tracker that’s in the game. You can only work on one delivery at a time. You must finish or cancel a delivery to start another.
For my on this game check out my video.
I give tips on how to fly the helicopter at 6:10