Welcome to ATP and the wonderful world of Gardening.
Growing veggies is very rewarding and nothing beats the taste of fresh from the garden.
That said, first off 8 by 8 is not nearly enough room for your list of everything you would like to grow. Watermelon alone would take up the entire 8 by 8 space. Same with Pumpkins. Okra is a large plant and squash takes up lots of room also. Sorry, I don't know much about growing corn but I do know you need enough of it to guarantee good pollination.
I see a good beginning in your picture but either decide on a larger garden or trim down your list. You could probably do the beans, all the greens, peas, some eggplant and peppers. Cabbage grows large and even broccoli and cauliflower should be spaced 18 inches apart.
Hopefully some of the other veggie growing members of ATP will see your post soon also and chime in.
