Generally speaking, only one student account is necessary. In fact, all user account roles in Jasperactive have a Student Dashboard associated with it. If you have a multi-role user account, as shown below with a drop down option, click the drop down arrow in the upper right of the screen and select Student. This depiction relates to Administrator and/or Teacher users who have the ability to "toggle" between user roles from one login.
If you only have a Student role user account, then you will not have a drop down option.
For various reasons, an individual may elect to create an additional user account in Jasperactive, and that is possible using a different email address. Of course, this would result in separate coursework activity tracking.