Beans and rice are cheap, chili is cheap, spaghetti is cheap, jambalaya is cheap, beef and potato or chicken and potato stew is cheap, gumbo is cheap. Buy whole chickens, learn to cut them up or have them cut. Bake it whole with a side of potatoes and corn. Frozen corn on the cob is cheap. Meatloaf is cheap.
That's 9 cheap easy meals right there, pretty much dirt cheap. Cake mix is a dollar, frosting @$1.29. You're not starting out with nothing, you must have staples, bake some cookies. Oatmeal and peanut butter cookies are very cheap to make. Plus you can make a grip of cookies in under an hour.
It's not hard. You have to want to do it.