Kendall,

This is a great question and there are several ways you could go about turning your hobby into a business.

1. Create a brand or at least a website to announce your new venture to the public. Then start sharing on social media (share pictures you've taken, pictures of clients you have permission to share or just interesting tips about taking pictures for hobbyists).
2. Team up with an existing company or individual that offers similar services (web and/or print design or similar) that may not be a photographer themselves. Ask them about offering your service to them for their current and future client work (taking product shots, or unique stock photos of places and people) that meet that need. It may not be enough to take it full time immediately but it reduces the risk of having to find all the clients yourself.
3. Compare your pricing to those in your geographic area that are offering similar services. Set your prices accordingly (you may charge less because you are building experience or because you are focused on landing new clients). You can always raise your prices later on after you have a good client base and more experience.
4. Focus on 1 or 2 niche markets only (at least at first). This can help set you apart from local competition that don't focus on those markets. Some possible examples could be, family portraits, weddings, events, corporate stock photography, nature or landmarks, product photography (e-commerce), food photography (blogs and restaurants). There really are plenty of areas to carve out a niche or two for yourself.
   1. You can also look to partner (exchange leads) with other photographers that don't overlap with the segments you focus on. Let's say you make a deal with a portrait photographer that you'll send them portrait client leads in exchange for them sending you wedding client leads (or something similar). You aren't really competing if you focus on different types of photography.