Dzonia Navigation Order - Previous Post, Next Post

I haven't been able to locate where to edit/modify the navigation order for previous post, next post, etc.

1) For example, from this page, http://morerootsthanbranches.com/covis/about-us/ , where do I (can I) edit the navi links for "<-- PREVIOUS POST" and "NEXT POST -->"?

2) And the navi links appear on some pages, but not others (it is here: http://morerootsthanbranches.com/covis/resources/contests/ but isn't here http://morerootsthanbranches.com/covis/about-us/honored-daughters/ )

Kind Regards,
Mariah

 

1.For your first issue

Navigation shown in the theme have default functionality of WordPress, Therefore it is not possible to add link in it.

2.For your second issue

Go to template-fullwidth.php present in your theme directory and add code given below

Code:

<nav id="nav-single"> <span class="nav-previous">
        <?php previous_post_link('%link', __('<span class="meta-nav">&larr;</span> Previous Post ', 'dzonia')); ?>
        </span> <span class="nav-next">
        <?php next_post_link('%link', __('Next Post <span class="meta-nav">&rarr;</span>', 'dzonia')); ?>
        </span> </nav>

Sending image for reference