People can recommend fast growing shrubs all day but they may not be appropriate, depending on your constraints (which are not mentioned.) You need to provide context. Most easily done by adding a wide shot picture.

I'm blanking. I can't think of anything that would put on that kind of height in one year - nothing you'd want, anyway, and nothing that would provide year-round privacy. The only thing that might do the job might be privet. There is a variegated privet that grows like a weed here in TN. But I'm not even sure, if you bought small plants of it, that it would grow that quickly when young. Most things I can think of would take about three years to reach a good size. I put in some Leyland Cypress, Green Giant Arborvitae and Yoshino Cryptomeria as a screen about two and a half years ago, and they are just now starting to do the job. These were touted as some of the fastest-growing evergreens, which is why I chose them. But even they took a couple of years. The Leyland has been the fastest among them.

I would like to suggest that you quickly fire or otherwise cancel the guy who is going to remove the wall. Then STOP, as Mad Gallica suggests! Then there are just a couple of things to do while you wait for spring. First is to measure your lot and draw up a plot plan that you can use for testing designs. This isn't hard to do, if you have a measuring tape, a straight edged ruler, and some graph paper (use 4 squares to the inch, it works best). Basically you'd want to include all the existing trees and structures, the location of the driveway & walks, utilities and the septic system components. Make copies of the base plan and then get some colored pencils and try different arrangements for "blocking" masses of plants. This will really help you to figure out where you really need borders, how wide you want them to be, and how tall the plants should be. Selecting the plants should come much later in the process. At the same time, go get a copy of one or more of Gordon Hayward's books; The Welcoming Garden is a good one. It describes how to get from square one (where you are) to having a house in a garden. It's got lots of useful techniques for deciding things like placement and depth of borders, selecting a style you'll be happy with, and how to make your design complement the locale. These little "passtimes" might get you interested in gardening to an extent you can't even imagine at this point. If that happens, we'll be here - egging you on. And by the way, welcome to the forum! Nice to see someone who has a blank slate - so many possibilities ahead of you.

How's the drainage? I have clay soils and grow some 100+ different species of trees and shrubs. Never fertilize, do not mulch. Bought 10 acres of a place with about 4 trees. Something like Chionanthus virginicus grows fine, is deer resistant, but needs well drained land. It absolutely needs sloping ground if you have clay. The shape is a mound about 15 ft. tall (after about 10 years from a sprig). Native evergreen Hollies (like Ilex opaca) make a decent screen after just a few years. If you want to put up a trellis, you can hide anything in 3 years with Aristolochia durior (macrophylla is a synonym). Doesn't spread all over, thrives in shade that is not to deep. If your idea is to plant it and forget it, forget it. Even the best situated, native or foreign plant needs a pruning to eliminate crossing or dead branches. Pruning to shape is also often needed. Spending every weekend is not required, but 10 hours/tree/year should be expected. (Pruning, weeding etc.)