How do I correct an incorrect permalink?

I learned that in the WP Query I had to specify page instead of quick_links which was the custom post type. In fact I completely removed the Custom Post Type UI and the plugin. It was all completely unnecessary.

I did not want every single page, just the news, about us and get involved so I researched if there was a way to grab specific pages, namely, those with a featured image and in the correct order and from what I found online I was able to piece together this code:

<?php $loop = new WP_Query(array('post_type' => 'page', 'meta_key' => '_thumbnail_id', 'order' => 'asc')); ?>

and it works:

enter image description here

error code: 523