This issue was resolved as of ~3:10pm PST on 10/23/2019. If you are still experiencing this issue after that point in time, please reach out to us here.
We have found that there is an issue with some new paid student accounts not displaying the "Classes" tab.
We're actively working to resolve this. In the meantime, if you have recently purchased a student membership using either an enrollment key or credit card and are affected, please reach out to us here and we can manually resolve for you.