You do not need to complete the course in just one session. You are encouraged to use several "log-on" sessions, but you should take the quizzes immediately after completing each module.
If you log off the site and return at a later time, you will re-enter at the "Learner's Menu" page. Choose the Basic or Refresher Course and you will be taken to the Grade Book to begin at the next required module. The course software will keep track of your progress. When you finish the quiz for a module, the software will give you a link to your next module or the opportunity to view the Grade Book.