I have made two types of camping pizzas, both of which were big hits with my camping companions.
Both involved buying a can of Pillsbury pizza dough (in the "cold items" section of your supermarket). Then I bought a squeeze bottle of pizza sauce by Primo brand, and some cheapo mozza cheese in the camping ice cooler. Finally, I tossed a small pizza cutter and a 12" metal pan in the camp gear.
First pizza--rolled out the dough onto the pan (it fits perfectly), sauced it, cheesed it, and then cooked it on my propane camp grill. You could also cook it over your firepit if you had some way to grab it with mitts or something. It's cheap, it's not gourmet, but it's pizza and it's camping.
Second "pizza"--I brought along one of those "camp cookers"--the ones for making toast, with two long handles and a small square piece of iron at the end of each. Normally, you close the iron squares together and make toast or whatever with them, but I used them to make pizza pocket types of things. I lined the iron squares with some more of the Pillsbury dough, added some sauce and cheese, and also some fresh basil I'd brought along (you could also just toss a spice bottle in your camping gear if you don't want to mess around with fresh basil). Cooked over the campfire, and it came out DELICIOUS. We couldn't make them fast enough for everybody!