It's a wonderful idea
There seem to be two different types of wildflower meadow. One is the generic type which comes out of a seed packet and contains lots of pretty flowers such as cornflower, rudbeckia, cornmarigold and so on. These may or may not be native to Britain or to your area. The other type of wildflower meadow is made up of flowers and plants native to your precise area and locality, such as you can see growing on the verges. The first type is clearly much easier to effect than the latter. Both will attract wildlife such as bees, hoverflies, wasps, butterflies, rabbits, voles and a whole host of birds. Which one you choose is of course up to you and depends on your reasons for planting the meadow. If it is just an extension of your garden, then the generic type is very pretty and easier to get going than the latter.
With all your disturbed ground, you are going to get a big burst of weeds, from seeds floating in on the wind, or brought by birds, weeds such as docks, thistles, ragwort, nettles etc, all stuff you don't want. If you sprinkle wild flower seeds on the same exposed ground the weeds will outcompete them straightaway. This is a big problem and I have no suggestions for dealing with it, sorry, except perhaps to cultivate the whole lot to kill any emerging weed seeds, then in the autumn, plant out actual wildflower plants, sourced from a nursery which gets its seed stock locally. Obviously plants v seeds, seeds win on cost.
There is plenty written online about the two types of wildflower meadow, with information and help available on how best to set about it. I think you would be best to do some research online, speaking to the professionals, as otherwise I worry you will be disappointed.