Agree with digitS. I will quote jal_ut, who is a regular here, does what I would consider small scale farming (as opposed to backyard gardening) and feeds his family from it. He always says if what you want is to grow food, the best things to grow, producing the most food are potatoes, squash, corn and beans. You should really think about growing some. (See James? I am listening!
And for me with a very small amount of space, doing succession planting is very helpful to get a lot out of a little space. So I put a lot of emphasis on early season crops. You have a bunch of cabbag-y stuff in there but not much else. What about broccoli, spinach, lettuce, kale? And absolutely put yourself in a row of swiss chard somewhere. One small row of chard will be all you need. Lettuce, spinach, etc bolt and are done when the weather warms up. The swiss chard just grows and grows from before the last frost until after the first fall frost. Very easy, very productive, nothing much bothers it.
And if you love dahlias, then sure grow dahlias. But they are native to Mexico (which is why we have to dig and store them for winter) and so they are of absolutely no use to our beneficial insects. To attract pollinators and predators (things that eat/ parasitize the "bad bugs") generally lumped as beneficials, plant (a selection from): cornflower, sweet alyssum, borage, anise hyssop (lovely in herbal tea blends), golden marguerite, marigold, mint and other members of the mint family like lemon balm (more tea!
), ironweed, members of the carrot family like parsley, fennel, dill, coriander, caraway, herbs like sage, oregano, thyme, basil, lavender. And that corn we mentioned is also good for this: Corn tassels produce large amounts of pollen that is a good protein source for many beneficials. Onions and garlic scattered through your beds help repel bad bugs. They take up very little space. Onion seed and garlic cloves would get planted in the fall, but you can do onion sets in the spring.
Have fun and keep us posted on how it is all going!