Display blog comments

Hi,

Check Settings – Discussion.
Keep in mind that your theme has to support comments too, so check if any option is available there or ask your theme developer.
If you do changes in Discussion settings it change things for new posts, if you would like to do changes for already published posts, use quick edit – select all posts and allow comments.

Edit: I just see that you use some kind of FB comment system, which hide default wp comments. So check that plugin for settings.