On this page of the guide, you will find information about obtaining fuel and ammunition in Mr Prepper.
In Mr. Prepper, fuel and ammo are scarce commodities. They are not required throughout the entire game, but they make it much easier for the most part. The ammunition used for firearms – revolver and shotgun. Fuel has much wider use: mining machines, cars and emergency generators in your base all require refueling.
The only way to get ammo is to buy it from Joe at the scrapyard (you unlock it when you bring glasses for Bob from the mine as part of a feature mission). You can buy almost 50 rounds of at a time – only cash can stand in the way. You'll find some ammo during your desert expeditions, but you'll usually use it all up before returning.
Ammunition cannot be manufactured. You can buy fuel from Joe, too. Unfortunately, a maximum of 5 units, and not even every day. There's quite a lot of fuel in the mines, though.
The general way to get large reserves of fuel is to get to the -4 level of the mine. You can use the digger to extract oil. In the home refinery (Workbench level 3) you will be able to create large quantities of useful fuel from it.