How to properly edit reverse pages in WP?

Question

WordPress

How to properly edit reverse pages in WP? Content is being pulled <?php echo get_post_meta( $post->ID, 'preview_company_image', true ); ?> <?php echo the_title(); ?> <?php the_content(); ?> I can't understand from where, I start changing one block and others change. Content is pulled from two files and connected:

while ( $posts_query->have_posts() ) {
    $posts_query->the_post();
    $i ++;
    if( $i%2 ) {
        get_template_part( 'components/items/success_story' );
    } else {
        get_template_part( 'components/items/success_story-reverse' );
    }
}

How to do it right so that you can change the content of one block without changing the other, and where does the text and headings come from?