First and foremost, you what to take care of legal issues. Register for a minimum of an LLC (Legal Liability Corp.) under your company name and get insurance. This will cover you and your personal assets in the event something happens or you get sued for something.
As for getting jobs, use a classified group within facebook. This is one of the fastest ways to get it out there in front of people that are closest to you and usually free. Find local realtors and provide a card. When I use to do aerial photography using my R/C plane and helicopter, I would go around and take photos of churches, businesses, and big sub-divisions and email samples to the owners to see if they would be interested in them without watermarks or edits. I did pretty well and had good luck. Plus you are going to want to fly anyways so why not take advantage of the footage you capture.