Summarize this article in one sentence.
Assisting a pro can help you learn effective coaching skills. Plus, they can give you advice on starting your own career. Check out your local tennis clubs or camps to see if any assistant positions are open. Public tennis programs are a popular summer activity for kids. These are a great place to start your tennis instructor career, and often hire instructors as young as 17 or 18. As a rookie, expect to start out teaching young beginners. Summer rec programs may have large classes of kids, which can be hard to manage, particularly as a first-time instructor. If possible, try to teach classes of only five or six kids. Some summer camps also offer jobs to rookie tennis instructors. Once you have some experience under your belt, you can apply for a more advanced position at a tennis camp or club in your area. Tennis clubs often offer lessons to students year round, and typically hire more experienced instructors. You might want to make tennis instruction a full-time job, do it on the side for a little extra cash, or make it a hobby. Consider whether you want to work with beginners or more experienced players as well. Then, choose a job accordingly. You might volunteer to teach lessons at your local youth center, apply for a full-time job as a high school or club coach, or give private lessons. You should also take your skill level into account when deciding on a path. For example, if you want to coach professional tennis players, you'll need to have played tennis professionally. On the other hand, several years of playing competitive tennis may be fine for coaching young kids or high school students.

Summary:
Assist a professional tennis instructor. Get a job at a public summer rec program. Teach at a tennis camp or club. Pick a position that aligns with your goals. Teach at your personal skill level.