At some stage in your academic experience, you will be expected you to submit coursework through Blackboard.
You submit coursework by adding text or uploading files to a Blackboard or Turnitin dropbox.
You can recognise coursework submission dropboxes by their icons:
Turnitin assignment dropbox icon
Blackboard assignment dropbox icon
Finding your coursework dropboxes:
You can access your dropbox through Assessment and feedback folder in the Course content area:
Through Gradebook
And in Calendar view and clicking on Due Dates
Submitting coursework to an assignment dropbox