All Class Central profiles are visible to signed-in Class Central members when created, but you can make yours private so only you can see it, or public so anyone can see your profile, including the courses you have marked as complete and your public Lists.
To choose, go to Your Profile (in the drop-down list when you hover over your image at the top right), then Edit Profile. Select the Private/Public/Class Central Community toggle under Profile Visibility, then select the Save button.
Reviews you have added while signed in to your Class Central account display your username and profile picture, whether or not your profile is public. Reviews added when not signed in are marked Anonymous.