I would amend my soil and plant as I've finished digging up that soil. You thus don't have to wait for construction and completion to get started growing. It's getting late to start broccoli and cabbage but still possible. You can plant the seeds in any soil you've prepared. It's a little early to plant lettuce and spinach. In my area I plan to start sowing these leafy vegetables starting slowly from mid August.
One problem this time of year is finding the seeds you want. The big box stores send their seed back to the supplier starting in early June it seems.
I would assume you don't have home made
compost if your just starting to garden, Options are buying bags, buying bulk by the truck load or finding free manure. I would never buy bags of any product to amend my soil as you can't control and or trust those who control what's in it. A good option if you need
enough is to buy
mushroom compost from a garden center. I'm paying $40 a cubic
yard and $40 for delivery. To give you an idea how much a cubic yard is; 2 cubic yards will fill a pickup truck well over the sides. The third option is to google horse boarding facilities in your town. The advantages are it's an excellent soil amendment and a wonderful fertilizer. The disadvantage is that I wouldn't grow
root veggies or leafy veggies in it till next spring if I amended my soil with it now. You
should also test it for herbicides by planting a few bean seeds in a mixture of your soil and maybe 20% of the manure. Do the test before you haul it. The manure will be free. I rent a pickup truck and it costs me $42 for the rental and the mileage I drive.
I have clay so cover the soil with three inches of manure or horse manure; which is manure used to grow a couple crops of mushrooms. I then dig it in by turning the soil over with a spade. It's better to turn it twice so I dig in 2 inches the first pass and an inch the second pass. If you have deep rich black soil then I'd only add an inch. I've never grown in sand but think I'd probably go with the same 3 inches of mulch. I leave the grass from the soil as it's the best soil I have. I try to get it to flip so that it winds up on the bottom. If you flip it so it's on the edge of what you dug it'll slide into the hole when you dig the next pass.
Good luck with your
gardening!
edited to add: From my experiences fencing won't keep out squirrels, chipmunks or raccoons as they'll climb over it. It will keep out
rabbits and possibly deer, but you don't have them.