2 copies of every picture

You haven't told us enough about your situation to answer your question.  My basic response is to select the duplicate copies in the Organizer and press the Delete button. A dialog will appear asking whether you also want to delete the duplicates from your hard drive. 

However, is your real question about finding the duplicates?

And how did the duplicates get imported into your catalog? Are they true duplicate copies of your photos and are they stored on different drives or in different folders?