A bag of potatoes and a bag of onions go along way. So does a bag of rice.
Fresh veggies are easy. Get a steamer insert and they'll taste great steamed.
Some frozen veggies are better than others, Corn, Green beans, Lima beans. Mix em' up.
Meat. Chicken with the bone on is cheaper and I think it tastes better.
Buy some pork chops, or cut up chicken, pack them separately each and freeze them.
Hamburger has a lot of uses, Burgers, chopped steaks, chili, tacos, etc.
Bookstores have cookbooks full of recipes that have four ingredients of less. Usually easy too. Helps you keep variety going...
Also ask girls to help you cook. There's a lead-in that I wish I thought of when I was single.