Tennis lessons for kids! 5 and 6 year olds can only join this class if they can hit the ball and rally a bit. For kids who are looking to start their tennis journey younger than this, then the Blue Stage Red ball class is the one to join. Coaching sessions are run by qualified Tennis Australia coaches around the country. Each lesson takes place in a nurturing environment which promotes participation and inclusion. They are run in small groups where kids are introduced to a sport they can play for life.