I don't want to make assumptions, but it sounds like you are doing this just for fun. Are you Alliance certified? I know it isn't illegal to teach yoga without a 200 hour certification, but it is really recommended to get certified first. Not just for the history and philosophy behind yoga, but to understand the each pose in terms of human anatomy and physiology, so you can make sure your students don't get hurt on your watch. Which also leads me to insurance. Even if you aren't certified, or maybe especially if you aren't certified, make sure to have yoga teacher insurance. All it takes is one student moving the wrong way and stressing out their knee or back, and you could potentially be on the hook for thousands of dollars of medical bills. Yoga can be really dangerous if done wrong, especially since it attracts people with preexisting conditions.