Students who excel having the direct attention of a teacher should sign up for a private class. Since you will be the only student, the learning pace is personalized to you. Classes will be intense, maximizing individual progress.
On the other hand, some students prefer a group class. This is a great way for friends and siblings to take an instrument together. If you are motivated by your peers, this is the class for you. There will be opportunities for both student collaboration and independent practice. Class will be conducted at a comfortable pace for each student, no matter what level he may be.