The easiest way is to add categories to pages.
You can use a plugin for that:
https://wordpress.org/plugins/add-category-to-pages/
Or if u are using a child theme, insert this code in functions.php in your child theme directory:
function myplugin_settings() {
// Add tag metabox to page
register_taxonomy_for_object_type('post_tag', 'page');
// Add category metabox to page
register_taxonomy_for_object_type('category', 'page');
}
// Add to the admin_init hook of your theme functions.php file
add_action( 'init', 'myplugin_settings' );
Another way is to create custom posts. there are plugins for this as well.
The difference is that a post can have multiple categories, while custom posts are like posts, or pages. in fact you are adding another post type beside the default posts and pages.