Single.php id calling

Hi guys,

So I created a gallery(custom) and well when you click on one of the images(that would be archive.php), which then redirects you to single.php(with information of the picture and itself).

Now what I can’t figure out is when you’d create an array and you’d need to fill in ‘page_id’ in the args now what I don’t get is when you click different images you get different id’s, what would I need to fill in the args? Here an example of what i’m trying to do:

<?php $args = array(
		'page_id' => '',
        'posts_per_page' => 1
      );
      $query = new WP_Query( $args );
      if ( $query->have_posts()) :
        while ( $query->have_posts()) :  $query->the_post(); ?>

<div id="paginawrap">
	<div class="pagina">
			<div class="clearfix"></div>
		<div class="col_3">
		<div class="thumbs"><?php if ( has_post_thumbnail() ){the_post_thumbnail('thumbnail');} ?></div>
			<h3></h3>
				<p></p>
		</div>
		<div class="col_6">
		<div class="position">
			<h1><?php the_title(); ?></h1>
			<div class="projectinfo"><?php the_content(); ?></div>
		</div>
		<div class="clearfix"></div>
	</div>
</div>

<?php endwhile; wp_reset_postdata(); endif; ?>