Some potential meals with emphasis on ease of preparation and cost:
Breakfast:
Oatmeal. Mix in walnuts and a banana.
Omelette with 2-3 eggs, cut up peppers, mushrooms, tomatoes, etc.
Lunch/Dinner
Sandwich ideas:
Peanut butter with banana and apple sauce
panini: lightly butter bread and pan, toast bread with cheese on pan while simultaneously grilling vegetables
Homemade soups:
Boil chicken or vegetable broth with your own vegetables cut into it. Include chicken/other protein. Add some grain (rice, quinoa, etc) if desired
Stir fry + whatever:
Stir fry peppers, mushrooms, spinach, whatever other vegetables. Mix with some grilled chicken/other protein and serve with some grain like pasta or rice. Whatever sauces you feel like.
Snacks:
Smoothie: blend frozen fruit, some fresh fruit, and greek yogurt
Trailmix: nuts, dry fruits, etc. Make it yourself and reduce salt intake
Fresh fruit, etc.
Buying tips:
Buy everything that doesn't expire quickly (grains, peanut butter, etc) in bulk every once in a while. You can get high quality stuff cheaply if you can mooch off of someone's costco membership or something similar. Buy whatever fruits or vegetables are on sale each week, although make sure you have a decent variety