If your users are registered in the User section of your WordPress site, the SCORM Cloud plug in will pass that information through to SCORM Cloud when they launch a course. In SCORM Cloud, you will see their WP information (First Name/ Last Name) in the reporting. And their email address will come through as their Learner ID.
If someone self registers for a course through your WP site - the plug in will ask them for their first name/ last name and email address which will pass through to SCORM Cloud.