Display Logo + Site Title + Description on Sydney Theme

Add this PHP code to child theme’s functions or use a functionality plugin like Code Snippets:

/**
  * Get site title and tagline
 */
add_action( 'wp_enqueue_scripts', 'sydney_child_site_info', 9999 );
function sydney_child_site_info() {

  $site_info = array(
    'name'        => get_bloginfo('name'),
    'description' => get_bloginfo('description')
  );

  wp_localize_script( 'sydney-scripts', 'site_info', $site_info );

}

Add the below jQuery code with TC Custom JavaScript plugin:

(function($){

  $('.site-header .col-md-4').append('<h1 class="site-title">'+site_info.name+'</h1><h2 class="site-description">'+site_info.description+'</h2>');

})(jQuery);

Then add this CSS code Additional CSS under theme customizer (Appearance > Customize) or use child theme’s stylesheets:

.site-header .col-md-4 > a {
  float: left;
}

.site-header .site-title,
.site-header .site-description {
  color: #fff;
}