Theme Architecture &
Content Management.

add_action( 'init', function() {
    register_post_type( 'service', [
        'label'       => 'Services',
        'public'      => true,
        'show_in_rest'=> true,
        'supports'    => [ 'title', 'editor', 'thumbnail' ],
        'rewrite'     => [ 'slug' => 'service' ],
    ] );
} );

<?php
/* Template Name: About */
get_header();
$hero = get_field( 'about_hero_title' );
?>
<section class="about-hero">
    <h1><?php echo esc_html( $hero ); ?></h1>
</section>
<?php get_footer();