How to avoid duplicate post in multi - php

Question

I am very new to Wordpress theme development and have found myself stuck at some point in coding.
I created two loops, where one loop has only 1 post and I styles it with bigger image, in the second loop I tried to fetch rest of the post but I am having some major problems.
In the second loop, the post of the first loop is also appearing, I want to avoid duplication.
When I go to page 2 or further, post from first loop is also appearing I want it to appear only on root page.
Below is my code.
First Loop
<?php
$bigi = array(
'posts_per_page' => '1',
'post__not_in' => get_option( 'sticky_posts' ),
);
$restp = new WP_Query($bigi);
?>
<!-- Loop started for bigimage single post -->
<?php if($restp->have_posts()) { ?>
<?php while($restp->have_posts()) { ?>
<?php $restp->the_post();
$post_id = get_the_ID(); ?>
<?php get_template_part('template/post/bigimage'); ?>
<?php } ?>
<?php } ?> <!-- Loop ended for rest of the post -->
<?php wp_reset_postdata(); ?>
Second Loop
<?php
$ropl= new WP_Query(array (
'post__not_in' => get_option('sticky_posts'),
'paged' => $paged,
));
?>
<!-- Loop started for bigimage single post -->
<?php if($ropl->have_posts()) { ?>
<?php while($ropl->have_posts()) { ?>
<?php $ropl->the_post(); ?>
<?php get_template_part('template/post/rop'); ?>
<?php } ?>
<?php } ?> <!-- Loop ended for rest of the post -->
<?php wp_reset_postdata(); ?>

Answer 1

This Should works. Change Query According Your Requirements.
<?php
$args1 = array('category_name' => 'test-cat-1', 'order' => 'ASC');
$q1 = new WP_query($args);
if($q1->have_posts()) :
$firstPosts = array();
while($q1->have_posts()) : $q1->the_post();
$firstPosts[] = $post->ID; // add post id to array
echo '<div class="item">';
echo "<h2>" . get_the_title() . "</h2>";
echo "</div>";
endwhile;
endif;
/****************************************************************************/
// array of post id's collected in first loop, can now be used as value for the 'post__not_in' parameter in second loops query $args
$args2 = array('post__not_in' => $firstPosts, 'order' => 'ASC' );
$q2 = new WP_query($args2);
if($q2->have_posts()) :
while($q2->have_posts()) : $q2->the_post();
echo '<div class="item">';
echo "<h2>" . get_the_title() . "</h2>";
echo "</div>";
endwhile;
endif;
?>