Is there any preparation I must do before taking the classes?

Yes, but very minimal though. Please ensure that your child takes the sessions from a closed and undisturbed space, and keep off distractions for maximum effectiveness. Ensure that there is adequate space to walk, lie down or stretch a little, as some of the practices involve standing, stretching, walking or lying down; a yoga mat would be preferable. For the meditation practices, your kid may need an upright chair plus cushions / pillows, rolled-up towels or blankets or a hard mat or bed on which he/she can sit or lie down when required. Also, a notebook and pen are required which he/she can specifically use for this course.