You can preview a Session as a student any time by simply joining the Session yourself through a new window or a second device, such as your smartphone.

Alternatively, you can start a Simulation in your live Session and click on the button to the right of it to open a new window and join as a student:

Pro Tip: If you do not want to be listed yourself in the student answers, you can simply locate your name on the Session Dashboard and click on the small 'x' on the left of your name to remove yourself from the Session.