You can always add a single dancer one at a time by going to Dancers>Add New Dancer in the sidebar. On this page you can enter the following information.
Dancer Name
Nickname
Date of Birth
Parent Name(s)
Email
Phone Number (up to 3 phone numbers)
Photo
Medical Information
Ticket Location
Understudy
Notes
Alert (a specific message you want to alert your check-in staff to, such as important medical considerations, a past due balance, or to send a particular dancer straight to the stage for respacing)