Is your simulation not allowing you to start? This could be due to a start date that has been implemented by your instructor.
Your instructor may want you to wait to begin on a certain date, so they will input a start date into their course. That start date will be the day you are allowed to begin your simulation.
Be sure to reach out to your instructor if you have any questions about start dates for your simulation, or reach out to Stukent Support at email@example.com if you are still having issues starting your simulation.