Whether a person is simply the guardian or emergency contact of a student, or if they are to become a member of the school, they need to be added as a person first.
Note the drop down list for “contact”. The contact is the person listed as the guardian/emergency contact for this person.
Supply as much information as your school needs for a specific person. This only pertains to general information. If they become a student then the specific membership information will be entered at that point on the add member page.