cannot view all tasks

Hello, I have been learning this product for a week now, and I have created tasks in several places: inbox, boards, HITs, Objectives, Roles. When I go to schedule my week or day, I cannot find a way to schedule tasks from all of these places. It seems you have to go to several screens before you can get to everything you have input.  Perhaps I'm not using this tool correctly.  I've been through all of the tutorials. Please help. Thanks!