I'd say you could easily fit all that into a 10' x 30' bed. 6 swiss chard plants won't make one meal of greens (at least not all at once), plant the whole package. If you use it in salads as part of the mix, you might be alright.
Depending on timing, you may be able to replant where you harvest something else. For example, where the lettuce come out plant more carrots.

g'day,

stick with raised beds, no-dig method, the ideal bed size about 6 meters longs and 1 meter wide.

check our bale garden presentation:

len

Here is a link that might be useful: lens straw bale garden

Good news! In Atlanta you won't have all of that in the ground at the same time. Tomatoes, corn, okra, cucs, squash, peppers all like the heat, but the other stuff you listed tend to curl up and die in summer, so tends to be in the spring and fall. So your bed doesn't have to be so big as to accomedate your whole list at once. It is likely too late this year for you to grow peas... Unless did you mean cowpeas? Those like summer also. Actually, I hope someone from more in your area chimes in, because I don't know if this year it might be getting late for the other cool weather spring crops...

Anyhow, I can't really intuit the space you will need, I always figure mine out by multiplying the spacing needed with number of plants I intend to grow for each type. Then I add in a little extra just to be able to keep things tidy. And I think 6 chard plants is plenty for 2, that's usually what I grew, but maybe we eat smaller portions of them than JohnDear. Or harvest it when it is bigger? Come to think of it, chard would stay inthe bed spring through to frost. Well, good luck!

Ha Ha Yes sunnibel7 I DO like my chard small... No bigger than the palm of my hand... IMO better flavor and tenderness. I also don't take off all the leaves at once. I go through my bed and select only the right sized ones. The too big ones get a trip to the compost pile. I find a small grocery bag full (or sack to you southerners) cooks down to a bowlful.

New to the neighborhood?
Go for walks in the evening. Check out who else is gardening in your hood. They will probably be out tending their garden and you can say something like: "Hi, we're new to the neighborhood. I like your garden...etc. etc." Ask them a lot of questions. There might even be a community garden nearby. Go to the nearest one and check out what everyone is growing and ask a lot of questions.
Think smaller rather than bigger. Small efforts by beginning gardeners have more chance for success.
My M.I.L. lives in Marietta and we moved as far West as we could until we hit the ocean. haha

For ease of gardening, you can't beat raised beds. Don't make them any wider than you can reach across to the middle. Bok choy grows better in cooler weather, and most of your others will grow in the summer. Tomatoes will need room. Consult your local Georgia Master Gardeners for free advice specific to your area.

http://www.caes.uga.edu/departments/hort/extension/mastergardener/index.html

You can find information on my blog as well. I have some information and photos of square foot gardening in raised beds.

Here is a link that might be useful: What's Growing On?

Aha! So that's it! Now Michael will have to consider at what size to harvest the chard!