Your notifications can be accessed by clicking on 'Notification's in the top right hand corner.
If you have unread notifications, the number of notifications will appear in red:
The notifications include when a teacher has assigned something to you. If there's a due date listed, it will appear here, as well in your 'Subjects/My Work' section:
You'll also receive a notification on the day an item is due, if you haven't already submitted it: