older posts in changed loop, posts_nav_link

You need to amend the custom query to take account of multiple pages. Eg:

<?php
$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args= array(
	'posts_per_page' => 6,
	'category_name' => 'News',
	'paged' => $paged
);
query_posts($args);
?>

thanks for answer, and help, but it doesn’t work,

maybe i will give the code that i have on my site, i tried many things, i tried this https://theodin.co.uk/blog/design/wordpress-pagination-wppagenavi-queryposts.html and one thing that now when i type in my url after whole url number eg: /2 i get the second page,

i also tried this https://weblogtoolscollection.com/archives/2008/04/13/define-your-own-wordpress-loop-using-wp_query/ but this doesn’t work at all,

I really don’t know where the problem is, and how to get it working, i really need this,

i also tried with this plugin wp=pagenavi, but it only works on first site,

that is my code after this first article adjust

https://wordpress.pastebin.com/eLMrKjrX

and this is before this first article adjustment, just the loop with category that i want to include

https://wordpress.pastebin.com/gEzyP5V4

Thanks a lot for help :]

Ok i used your code, man thank so much, i just have to adjust it a little, but it works, my code looks like this:

<div>
			<?php
				//The Query
				$paged = (get_query_var('paged')) ? get_query_var('paged') : 1;
$args= array(
	'posts_per_page' => 3,
	'category_name' => 'czytelnia',
	'paged' => $paged
);
query_posts($args);
				 while ( have_posts() ) : the_post();
			?>
			<div class="box4" id="post-<?php the_ID(); ?>">

				<div class="title4">
					<?php $preview = get_post_meta($post->ID, 'preview', $single = true); ?>
					<h2><a href="<?php the_permalink() ?>" title="<?php the_title(); ?>"><?php the_title(); ?></a></h2>
				</div>
				<div class="sentry4">
					<?php $preview = get_post_meta($post->ID, 'preview', $single = true); ?>
					<img class="ethumb4" src="<?php bloginfo('stylesheet_directory'); ?>/timthumb.php?src=<?php echo $preview; ?>&h=100&w=290&zc=1" alt=""/> 

					<?php the_excerpt(); ?>
						<div class="clear"></div>
				</div>
							<div class="sinfo4">

				<div class="rmore4"><a href="<?php the_permalink() ?>" title="Permanent Link to <?php the_title(); ?>"> Więcej... </a></div>

			</div>
			</div>
			<?php endwhile; ?>

<div style="text-align:center;">
<?php posts_nav_link(); ?>
</div>

		</div>

</div>

thanks