BrightTALK does not certify CPD credits, that responsibility lies with the channel owners and/or presenters of the webcasts you view. Some do choose to award points for participation in their events. However, this would be carried out independently of BrightTALK, so we would not be able to issue certificates or verify attendance.
However, you can get a simple list of the webinars that you have viewed if you go to the "Viewing history" page using the link on the left side of the MyBrightTALK homepage.
For information about entering your ISC(2) member number into BrightTALK, refer to this support article.