All of the courses at lagunita.stanford.edu/courses are offered free of charge. If you have paid for a class, it was likely offered through another Stanford department or group.
If you are taking the XEDUC115N How to Learn Math: For Teachers and Parents course through the Stanford Center for Professional Development, your course may take up to twelve hours to show up on your dashboard page at lagunita.stanford.edu/dashboard. If the course has not shown up in that time, please send an email to email@example.com to request assistance.
If you are taking a Continuing Medical Education course, make sure you are logged in to cme.class.stanford.edu (and not just regular lagunita.stanford.edu). Once you have logged in there, you should see your course at cme.class.stanford.edu/dashboard. If you don't see the course, use the Help tab on the top left of the page to request assistance.
If you paid for a course that isn't How to Learn Math or a CME course, you most likely are taking that course through a different platform, such as Coursera or NovoEd. Those sites are separate from ours, so you will have to contact their help centers if you are having trouble with one of their courses.