You're doing 'something' wrong, btu based on the info you've given, I have no idea what.
First of all, CAN people comment? Quick test, no tech skill needed. Log out. Go to a new post. Is there a comment box? If not, then there's the problem you need to solve.
Second of all, what did you pick in /wp-admin/options-discussion.php for "Default article settings"? Is the box checked for "Allow people to post comments on new articles"?
Third, this is not the SUPPORT fourm. It's the ideas forum, looking for new ideas for WP. You need support. Post in http://wordpress.org/support