Affinity Cruises manages the onboard activities, and Cruise Planners at SandlerTravel.com manages the purchase of the cruise and payments on the booking.

All amenities for the cruise (such as drink packages, excursions, gifts delivered to the room, etc.) are purchased through Carnival directly.  You will need to log in to Carnival.com to manage these purchases.

If you do not have a Carnival.com account, you can create one very easily by following the instructions there.  You then add your booking number to that account to manage the onboard amenities.  You will also need to have this account in order to complete your check-in and print your boarding documents.