It also helps if your clothing has few seams, or flat seams with small stitches. For the few areas that still rub use a lubricant such as Runners Lube, Body Glide, etc. These are especially helpful at the bra line and under arms where the arm hits the side of your breast. Some people use petroleum jelly, but I don't like the feel and it doesn't work as well. This product will sooth the burning, protect the area so you can keep on walking, and it promotes rapid healing.
People eat a wide variety of things on their distance walks.
Some carry real food such as a sandwich, others will eat only candy. Some popular food items include jelly beans, gummy bears, raisins, cheese, granola bars, bagels, all kinds of sports bars and gels, etc. I personally like the Power Bar Harvest Bars and Clif bars. Break them in half and put them in zip lock bags. You should be eating small portions fairly often.