In regards to registration please contact the institution that offers the course to get more details on certification, cost, registration, etc. You can then browse the results to find your course of interest. Clicking the course title will give you more information about the course. Good luck in your studies. We are not the course developers, but list courses available from over 1200 institutions world-wide.
Levels vary from kindergarten to post-doctoral.
In regards to registration please contact the institution that offers the course to get more details on certification, cost, registration, etc. You can then browse the results to find your course of interest. Clicking the course title will give you more information about the course.