Hi, and welcome. Have you done any digging to see what the soil profile looks like? I think that would be the first step, to dig a hole, like maybe 18 inches or two feet across, and as deep as you can. Then look at the soil around the hole. Do you see layers that are different colors or textures, are there a lot of rocks, how deep is the topsoil layer? ( that is the darker layer on top, if you are lucky it might be several inches or even feet--I actually don't have any where I am
gardening). How much organic matter is there (the bits of leaves, grass, and little chunks of partially rotten
wood, etc).
That
should also tell you if you have a layer that is compacted. But whatever you find can be improved by adding lots of organic matter, best done as a sheet mulch of layers of organic matter, or by covercropping, growing plants to cut down for mulch rather than digging it in, which causes the little soil critters to go on a rampage and burns up the organic matter very quickly.
A lot of gardeners don't even worry about compacted layers, or rocky soil, etc, they just build up a thick sheet mulch, or garden beds on top of the ground, either with sides made of rocks, logs, boards, etc., or just mounded. I just watched an interesting
video on youtube where the folks built sides for garden beds out of old
pallets, and lined them with black plastic, then filled the centers with organic matter and soil. It was an extremely productive garden. Another video I saw showed someone dumping piles of
compost etc on an old parking lot, and growing lots of sweet potatoes in the mounds.
Other folks lay down waste wood, broken or pruned branches, rotten
firewood, sticks, etc and cover the pile with soil, compost, manure, etc, and plant on the sides of the mounds. Check out the
Hugelkultur forum for more info on that. So you may not need to do any digging or tilling at all.
If you have access to the book,
Gaia's Garden, by
Toby Hemenway, maybe from the library, he has good simple explanations for a lot of these methods and ideas.
A lot depends on the climate and
water, etc of your garden. I would suggest picking an area close to the house, water lines, etc, and just try a small bed or two using whatever idea looks doable, and plant some seeds or plants and see what happens. Once one bed gets started you can always add another, maybe try another method and compare results.
Good luck. I love my garden, just to walk around and see what is growing is a good way to let off stress. Of course I love the fresh food too, but that is almost secondary to the pleasure of just hanging out in the garden, watching the birds and flowers, etc.