"There is only one success … to be able to spend your life in your own way." - Christopher Morley
I love this idea because it rings true. Choose your life rather than let others decide for you. I chose tennis first and last and it's given me many years of happiness.
If tennis also moves you then here are some ideas.
Competition
If you want to play professionally then you have your work cut out for you and if you haven't reached it by your mid 20's it is likely you never will. Even if you do you should plan on coaching as your follow on career if you never make your mark as a household name or earn enough beyond paying your bills to set your future in comfort. The odds are against you in this.
Acquiring Tennis Knowledge
Knowing all this you really should hone your teaching and coaching skills at the same time you progress as a player. Read all you can on the subject of tennis so you'll have a strong background in the history and overall general knowledge of the game.
Master Your Craft
Study all you can on coaching and teaching tennis so that you can self coach and later help others achieve their dreams on the court whether that means U.S.T.A. leagues, amateur tournaments, or professional play.
Reading, watching tennis instruction videos, and watching tennis matches will help you master your craft and part of your goal as a Tennis Lifer is to know and understand as much as possible about this wonderful pastime and avocation.
Share Your Knowledge
If you love this sport it should be an easy decision for you to teach others and share your knowledge either for your way of making a living or as a volunteer.
Enjoy Your Time
Play as often as you like and find a practice partner that makes your time on the court fun. Avoid stressful circumstances like competition if you are now past that phase of your tennis career. Just enjoy hitting balls and focus on your own precision.