Here's a typical grocery list of what I'll buy for the week:
Citrus fruit
Bananas
Cereal (hot or cold), toast, or English muffin
Almond milk
Loaf of bred
Bag of spinach (I use this for my sandwiches instead of lettuce, it's better for you)
Deli meat
Chips
Yogurt
Soda
Water
Ground turkey, salmon, chicken breast, steak, etc.
Random veggies (fresh and/or frozen, depends on what's on sale for the week)
Kale (can be cheaper than lettuce and much better for you)
It's all a matter of how much time you're wanting to spend preparing your meals every time you're eating. That and join a savings club w/ the local grocery story, this allows for fluctuation with what's on sale etc.that you can mix your meals up. Just remember, when you buy processed food, you're usually paying for the convenience, but it's almost usually the most unhealthy.