My advice:
1) Plan your meals to include leftovers. That way, quick meals, lunches, etc. contain what YOU put into them.
2) Get a crock pot. Let IT do the cooking while you run your errands. Plenty of great recipes for them.
3) We eat BAD food because it is also CHEAP food. However, there are plenty of ways to economize on food. a) Shop sales (many stores have BOGO deals, buy one get one free, etc.), b) use coupons (seriously, once you start, much easier to maintain), c) when on sale, stock up!, d) mix meat into dishes with pasta or rice to stretch it. Normal meat meals are like a lb a person, but if pasta or rice involved, can get away with much much less (making it cheaper), e) include veggies! (canned and frozen veggies are cheap, but fresh ones can cost, so be frugal).
4) Get a set of GOOD nonstick pans. Your food will cook better, and they'll be easier to keep clean. Or can start with just ONE large frying pan. Remember the other rules, cook with the idea of leftovers, for example.
5) Learn the value of premade sauce and marinade mixes. These are a godsend for cooks with little time. McCormick makes a ton of them, and they are delicious. Transforms ho-hum chicken into a real dish, for example.