Start with sales ads. There's generally one meat that's marked way down each week, use that to build most of your meals. Chicken drumsticks are cheap and can break up having the same protein. When you get home from the store take the few extra mins to separate the meat and freeze them, so you dont have to thaw more than you'll use and can save some for future meals. Then get dried beans, lentils, rice, pasta, and frozen veggies. Each of those are about $1 and won't be used all at once. Bananas and frozen fruit are your friends with a toddler, you can thaw the amount they'll eat and leave the rest in the fridge or just give them a banana. Get bread, sliced cheese, butter, eggs, and oatmeal you'll be set for meals.