Please log in to your LMS account. Go to the Courses tab. From the drop-down list choose My Course. Click Go To Course. Check whether your session is live or not. (Orange tab on the right side of the screen)

Click on the Live Session button to join the session. 

please check your inbox for a mail from Acadgild that has the joining details for the session. Click on the link in the mail and you should be able to join the live session.