To open your collections, select Berk's Duties (Viking Helmet Icon) at the bottom of the screen. Completing a collection will give you specific Dragons or resources. Most Collection Items will be found either on Trader Johann's Ship or by sending Toothless on a search. If you want to search for a specific item, simply click on it and it will show you where to get it.
Gearscan only be received when Defending Berk or Sending dragons on Journeys.