Comment Section Is Not Visible

First, go to your blog dashboard -> Settings -> Posts, comments and sharing settings and check if Comment Location is set to something other than "Embedded". If it is, set it to "Embedded" and save the changes.

If the comments are still not appearing, open one of your posts without a comment section in the editor -> click on Options from the right and check if Reader comments is set to "Don't allow". If it is, set it to "Allow" and save the changes.