Food:
With a heavy cast iron skillet, you can cook just about anything over the fire. If you're at a campground, many permanent fire rings have grates that you can place over the fire to rest a pan on. You have to be really careful about moving the skillet around to control the heat, but it works. There's nothing like bacon and eggs over the fire in the morning! We also like to do thick-style canned chili over the fire...Just open the cans and set them on the grate. Stir occasionally, and eat directly from the can.
Also, if you want to buy a little gear, camper pies are a blast. You take bread (the size and shape of good old wonder bread works best...but I'm sure you could find a GF alternative for yourself), make a sandwich (we use pizza sauce, pepperoni and mozzarella cheese), and coat the outside with soft butter or margarine. Put it in a pie iron from the sporting goods store, and cook in the fire until the bread is toasty and sealed into a pocket. For a dessert pie, fill with your favorite pie filling. Yum!
And remember trash bags and eating utensils. If you're going easy, bring all disposable. If you need to wash dishes, you'll want to bring a way to boil water, a couple of dishpans (one for washing and one for rinsing), and some dishsoap and towels.