Talk to the NRA, they assist in range development. If you build it, they will come. You'll need to survey the whole parcel, fence the downrange portion to keep folks out, topo survey it for design and layout, you're going to have a lot of expense up front. Legal and insurance is not going to be cheap, either.
Instructors, range masters, shopping, events, lots of things to offer. Sanitation, parking, shade, retail sales, licensing, gun rentals, you name it.
Check out what the population is within a one-hour drive, two hours, four hours, and a full day on the road. Is lodging available for destination visits? If not, don't plan on big events.