Your students will only see their own information, and cannot see information about other students in your studio. Students can see their own lesson schedule, lesson history, etc. Parents will see this information for all of their children, as well as billing information such as their own payment history. Teachers will see the schedules of the students they are teaching as well as lesson attendance. Staff members will see almost everything you see.
If you want a certain group to have different permissions than they currently do, you can customize who can see what, by clicking “Settings” – “Permissions”