Creating a “category” of featured posts

To answer the latter part of the question, you can use this article for reference: http://www.wpbeginner.com/wp-tutorials/how-to-display-the-latest-sticky-posts-in-wordpress/ and also the WP documentation here: https://codex.wordpress.org/Sticky_Posts

The sticky posts can be obtained with:

$sticky = get_option('sticky_posts');

Then the query:

$args = array(
    'post__in' => $sticky,
);
$query = new WP_Query($args);

That will give you what you need