Remove links under main page
These links are navigation links, so called "breadcrumbs". They inform the site visitors where they are on the site.

You are using the Bartik core theme -- take a look at /sites/themes/bartik/templates -- there is a file page.tpl.php. On about line 176 the following code

&lt;?php if ($breadcrumb): ?&gt;
  &lt;div id="breadcrumb"&gt;&lt;?php print $breadcrumb; ?&gt;&lt;/div&gt;
&lt;?php endif; ?&gt;


renders these breadcrumbs.

You could comment or remove these lines to avoid rendering navigation links. If you make changes to theme files remember to flush cache to see the changes.

But a better solution would be to create a Bartik subtheme (because each time you update the Drupal core, all your changes made to this file will be overridden, I would also not recommend to touch core files).

You could consider to choose another theme which has additional settings options like for displaying breadcrumbs.