Even if you could afford the set up costs, the insurances, the cost of having on site emergency services, a place to do it etc etc, you still have the biggest battle ahead, local councils planning application. You would be beaten down via noise pollution, local residents [yes, even within miles] and basic bureaucracy. Even established venues are having problems nowadays.
I honestly wish you luck but i fear that modern trends of hatred towards cars, induced by the overwhelming mutterings of the minorities would be your biggest stumbling block, if not the finances.
As suggested below, it may be better to find a local motorsport club, there are more than you might think, and see what they have to offer.
I admire your plan to try to do something about the idiots on the roads but ultimately, they will be idiots wherever they are given somewhere to drive.