exclude-first-post.php

<?php
function terrawise_exclude_first_post_from_query($query) {
    if (!is_admin() && $query->is_main_query() && (is_home() || is_category())) {
        if (!$query->get('exclude_first_post')) {
            $first_post = get_posts(array(
                'post_type' => 'post',
				'post_status' => 'publish',
                'posts_per_page' => 1,
            ));
            if (!empty($first_post)) {
                $first_post_id = $first_post[0]->ID;
                $query->set('post__not_in', array($first_post_id));
                $query->set('exclude_first_post', true);
            }
        }
    }
}
add_action('pre_get_posts', 'terrawise_exclude_first_post_from_query');
?>