How do you eat healthier when you’re kinda broke?

For context; I’m a single mom of one teenager and a public school teacher so I make enough to pay my bills but not much else. I’ve never really eaten well, but now that I’m almost 40…the pounds are packing on! I just got done reading a post about eating healthy and how that makes others feel less tired and have more energy. However, I have no idea how to 1) cook healthy meals that actually taste good and 2) what to buy that I can afford. I spend about $450 a month on groceries…so that’s more or less the budget I have for food.

Can anyone give me any ideas on what I can make that’s healthy?