Don't worry about having lots of food when you first start out. The average American family has less than a weeks worth of food in their home. I highly recommend working towards having two weeks as a first goal. Look at what you already have and use. Determine what stores the best and start buying a little more of it each time you go to the store. Eat the oldest food so you rotate your stocks. I have over three months of food in my house by only using this method. This is one of the easiest things you can do to become more prepared today.
What’s the bare minimum you need to navigate across land? For most people, that would be a compass and map. A basic road map is sufficient to get a rough approximation of the lay of the land. More detailed relief maps can help plan for elevation and estimate possible water sources but they also take up more room in your pack. Waterproofed or laminated maps are also extremely helpful. Lensatic compasses are the most reliable for little money. If possible, a compass and protractor are also extremely helpful for route planning. Obviously, not as essential but nonetheless useful.