Simple! Just click on Reports, then on Visual Reports. From there, you can choose to run a report on either courses or on assessments.
The Courses report gives a visual breakdown of a specific course and includes details about time spent per item and assessment scores.
The Assessment report breaks down assessments by score, amount of correct/incorrect answers per question, as well as detailed breakdown of the answers given for each multiple choice/true or false question.
NOTE: Assessment visual reports will contain information for all users that have ever attempted the assessment, even if they are no longer enrolled in the course. If you wish to remove their information, you will need to either delete their assessment attempts or delete the user altogether.