in case you want to enroll in piano group lessons, you are responsible for finding partners, who are approximately of the same age and at the same level. Also keep in mind that learning how to play instruments usually supposes private (one-to-one) lessons, as there is much more than finding correct notes to it.
It’s more practical to enroll in shared 45-min long lessons for 2 students than to look for groups.
online music lessons may be somewhat useful in case the learner has already devoted at least a couple of years to studying an instrument and wants to just learn new pieces. They may satisfy adult learners or advanced children. When beginners try to learn online, the lessons turn to be mostly “theoretical”.