WordPress – Create single posts template single.php

single template is used post/post-type inner page, for more read WordPress template hierarchy.
Create single.php in theme directory and call get_header and get_footer function to include header and footer section of theme.

<?php
get_header();
//next code will be here 
get_footer();
?>

Start Loop for single post

if (have_posts()) {
	
	while (have_posts()) {
	the_post(); 
	$post_permalink = get_permalink();
	$the_postid = get_the_ID();
	$post_title = get_the_title();
	$post_thumbnail_src_html ='';
	if (has_post_thumbnail()) {
		$post_wp_get_attachment_image_src = wp_get_attachment_image_src(get_post_thumbnail_id($the_postid),'large'); 
		$post_thumbnail_src_html = '<div class="col-xs-12 text-center"> <img src="'.$post_wp_get_attachment_image_src[0].'" /><hr /></div>';
	} 
//next step code will be here
}

Create breadcrumb and add links

Add links and create breadcrumb.

<div class="col-xs-12 nlrp">
	<ul class="breadcrumb">
		<li class="breadcrumb-item"><a href="<?php bloginfo('url');?>">Home</a></li>
		<?php
		$categories = get_the_category($the_postid);
		$separator = ' ';
		$output = '';
		if (!empty($categories)) {
			foreach ($categories as $category) {
				$output .= '<li class="breadcrumb-item"><a href="' . esc_url(get_category_link($category->term_id)) . '">' . esc_html($category->name) . '</a></li>' . $separator;
			}
			echo trim($output, $separator);
		}	
		?>
		<li class="breadcrumb-item current"><?php echo $post_title;?></li>
	</ul>
</div>

Show post title and post content

<h2 class="heading"><?php echo $post_title; ?></h2>	
	<div class="col-xs-12">
		<?php echo $post_thumbnail_src_html; ?>
		
		<?php the_content();?>
	</div>
	<?php
	} 
// Following closed curly brace bracket is from if (have_posts()) { code
}  
else {
?>
<h2 class="heading">Sorry posts not found</h2>
<?php	
}
comments_template();