If your system requires teachers to register their students, you must create teacher accounts so that they can log into the system. When you create a teacher, a system user is created automatically, with "teacher" privileges.

If your system allows parents to register their students, then you will need to create a user account for the parent to register their child. Some versions of the system allow people to create accounts. However, allowing anyone to create accounts is not recommended, as bad actors can try to create accounts and log in to steal information. 

For systems that have additional fees for non-members, you can mark the new teachers as "non-member" when you create them, or you can edit the teacher and mark them as "non-member." 

Typically, chairs will send me an excel sheet with a list of teachers to import. But if you wish to create a few teachers or useres, that can also be done manually. See this video.