It's not hard and if you keep it grass roots to begin with will stay that way.
A friend and I started it where I live. First is to locate a lot, usually a city owned is the best to start out with as buisnesses require alot of hoops to jump through.
Here we use a lot at the softball complex and got with the city street department who loans us the needed cones (after securing the lot use from the parks department).
The hardest part was the event insurance which runs about 400 per day for 1 mil coverage (some cities have or will donate this the first time. Or get with local car clubs who also have this type of insurance for shows).
You will also need disclaimer forms, etc.
Also realize a persons car insurance does not cover them in racing events, they are on their own if they turn turtle.
ours is total word of mouth and we still have 25 or more cars show up. best free advertising.