Once you have entered the ticket ID Number, you may click + to add another. Once you have added all numbers, you will click "Next" to Assign the ticket number to a name. This ticket number can be linked to a Magic Band.
Magic Bands are not required but make life A LOT easier In the parks.
When ticket cards/card #s are passed out, go to "My Plans" and click "Link Tickets".
Chaperones, I would suggest linking your group's ticket #s to your MyDisneyExperience