As a parent, you can start testing hand-eye coordination with your child as early as 3 years old, simply by tossing the ball to them. We recommend that you interact with your child first using just a tennis ball on a court. Then, progress to letting them handle a racket to hit the ball with a simple bounce and then move further away from them on a daily/weekly basis to see if they can hit the ball. The goal is simply to hit the ball, not to hit over a net in the first few months.
There are four racket sizes for youth which are calibrated for height and weight. Please get the smallest racket possible initially so that your child gets used to handling this without extra weight. As they grow, the tennis racket will grow. Consult with your coaching professional.
There are three types of balls for youth play prior to the 'faster bounce' standard tennis ball: