we buy the Jiffy pop thingys which work great on a camp fire.
If you ever made home popped in a kettle with oil, then I would say, do it that way. Only difference would be outdoors.
If you have never made popcorn without a microwave or air popper, you may want to try it out at home first. all you need is a 4 quart kettle with a tight fitting lid and some oil and the popcorn.
measure out enough popcorn so that it will just cover the bottom of the kettle in a single layer. Dump it back into a cup. pour in some oil. You want enough so there is about 1/8 inch layer in the kettle. add 2-3 kernels of the popcorn and set the kettle over low heat. When the 2-3 kernels pop, add the rest of the measured corn and close the lid. gently shake the kettle back and forth on the stove burner until the rest of the corn begins to pop. As the popping gets faster, you may want to shake a bit more vigorously. when the popping slows way down to only 1 or 2 pops every 8-10 seconds, remove from heat and dump into a large bowl Top lightly with melted real butter and what ever else you enjoy.