It's known around here that people make bulk accounts to enroll in free courses so they can sell the account once the course goes paid.
People who enroll in a course are less likely to start it since they don't see the value.
People see less value so give you reviews that might not be what you're expecting.
I think one of the best ways to get your initial reviews is to head to Facebook or Reddit and help a related group with their problems. Once you gain trust, let them know that you have a course that may help. Don't advertise right away as you'll just most likely get banned and blocked from the group or subreddit.