Buy real food and always have it available
Stay within the fruit and veg isles when you go shopping, maybe go into the dairy for some eggs, skip the bakery.
If you can’t cook or don’t have time, buy pre-sliced vegetables. They’re slightly more expensive but will make a healthy eating choice easier by eliminating the step of having to chop things before you eat them. That detail that might seem insignificant, but this nutritional strategy makes a difference.
Eliminate the hurdles. Make the good choices convenient and as easy as possible.
The good choices should be the easiest decisions and the bad ones the hardest.
Research into meal prep companies; there are meals out there that come totally cooked and are healthy.