In the first scene, when you're getting the tour with the scrap robot, follow him all the way through to the small campsite with the car up on the lift next to the burning tires. Collect all the loot (guns, money) along the way and kill all of the guys. Once everyone is dead simply pause the game and go to exit. It will save your character (level & loot) and start you at the very beginning upon loading your game. You can repeat this as many times as you'd like!