Hide comments section "You may use these HTML tags"

This is from WordPress, you can hide it by putting the following under Appearance > Customize > Additional CSS:

p.form-allowed-tags {
display: none;
}

If you want to remove it entirely (using a child theme) the template file is: templates/comments.php

Also, if you are looking to disable comments on pages or posts please refer to this article.

http://www.cryoutcreations.eu/wordpress-themes/wordpress-tutorials/wordpress-disable-comments-tutorial

Cheers!