Genesee_Baker

After a bunch of research, I finally figured it all out. In the functions.php file I put the following code:

function header_widgets_init() {

	register_sidebar( array(
		'name' => 'Below Navigation',
		'id' => 'below_nav_widget',
		'before_widget' => '<nav>',
		'after_widget' => '</div>',
		'before_title' => '<h2 class="rounded">',
		'after_title' => '</h2>',
	) );
}
add_action( 'widgets_init', 'header_widgets_init' );

Then in the header.php file under my nav section I put:

<?php if ( dynamic_sidebar('below_nav_widget') ) : else : endif; ?>

And everything worked! Good luck!