If you are having trouble logging in to your purchased courses, you may have chosen to create your login as a MyTeachable account. You'll want to choose that option for login. You can see that option in the bottom right hand corner of the login area. Once you’ve logged in via that option you should be able to view the course.
With either login option, you will have the option to select “Forgot Password.” This should help you reset it if you need to.