How do I get the author bio to show up on posts?

If you want to display the Author info like our demo, you can do as the following:
Open the content-single.php file. remove all the code then add the new following code:

       <?php
/*
* The template for displaying content on the search page.
*/
?>
<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>
<header class="entry-header">
<h1 class="entry-title"><?php the_title(); ?></h1>
<div class="entry-meta">
<?php dw_focus_posted_on(); ?>
</div><!-- .entry-meta -->
</header><!-- .entry-header -->
<?php if( has_post_thumbnail() && ! has_post_format('video') && ! has_post_format('audio') && ! has_post_format('gallery') ) : ?>
<div class="entry-thumbnail">
<?php the_post_thumbnail(''); ?>
</div>
<?php endif; ?>
<div class="entry-content">
<?php the_content(); ?>
<?php wp_link_pages( array( 'before' => '<div class="page-links">' . __( 'Pages:', 'dw_focus' ), 'after' => '</div>' ) ); ?>
</div><!-- .entry-content -->
<?php dw_focus_post_actions(); ?>
<footer class="entry-meta entry-meta-bottom">
<?php if ( get_the_author_meta( 'description' ) ) : ?>
<div class="author-info">
<div class="author-avatar">
<?php echo get_avatar( get_the_author_meta( 'user_email' ), 90 ); ?>
</div><!-- .author-avatar -->
<div class="author-description">

<h2><a href="<?php echo esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ); ?>" rel="author"><?php echo get_the_author(); ?></a></h2>
<p class="description"><?php the_author_meta( 'description' ); ?></p>
</div><!-- .author-description -->
</div><!-- .author-info -->
<?php endif; ?>
</footer>
</article><!-- #post-<?php the_ID(); ?> -->

Notice: To change the author info, you can log in to Dashboard > User, find the Contact info section.
See the screenshot: