Moving menu below banner

Hello,

You need to edit the php file for achieving that.

You can replace:

<nav id="site-navigation" class="main-navigation" role="navigation">
		<div class="col-width">
			<h1 class="menu-toggle"><?php _e( 'Menu', 'govpress' ); ?></h1>
			<a class="skip-link screen-reader-text" href="#content"><?php _e( 'Skip to content', 'govpress' ); ?></a>

			<?php wp_nav_menu( array('theme_location' => 'primary', 'menu_class' => 'nav-menu' ) ); ?>
		</div>
	</nav><!-- #site-navigation -->

	<header id="masthead" class="site-header" role="banner">
		<div class="site-branding col-width">
			<?php if ( get_header_image() ) : ?>
				<a href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home">
					<img src="<?php header_image(); ?>" width="<?php echo get_custom_header()->width; ?>" height="<?php echo get_custom_header()->height; ?>" alt="">
				</a>
			<?php endif; // End header image check. ?>
			<h1 class="site-title"><a href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a></h1>
			<h2 class="site-description"><?php bloginfo( 'description' ); ?></h2>
		</div>
	</header><!-- #masthead -->

With:

<header id="masthead" class="site-header" role="banner">
		<div class="site-branding col-width">
			<?php if ( get_header_image() ) : ?>
				<a href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home">
					<img src="<?php header_image(); ?>" width="<?php echo get_custom_header()->width; ?>" height="<?php echo get_custom_header()->height; ?>" alt="">
				</a>
			<?php endif; // End header image check. ?>
			<h1 class="site-title"><a href="<?php echo esc_url( home_url( '/' ) ); ?>" rel="home"><?php bloginfo( 'name' ); ?></a></h1>
			<h2 class="site-description"><?php bloginfo( 'description' ); ?></h2>
		</div>
	</header><!-- #masthead -->

	<nav id="site-navigation" class="main-navigation" role="navigation">
		<div class="col-width">
			<h1 class="menu-toggle"><?php _e( 'Menu', 'govpress' ); ?></h1>
			<a class="skip-link screen-reader-text" href="#content"><?php _e( 'Skip to content', 'govpress' ); ?></a>

			<?php wp_nav_menu( array('theme_location' => 'primary', 'menu_class' => 'nav-menu' ) ); ?>
		</div>
	</nav><!-- #site-navigation -->

Thank you.

Thank you. But would creating a child theme be safer? What would I put in a child theme if true (sorry, I’m a real beginner here!).

Hi, I got it! Thanks. (I added a child theme.) Quick question, though: how do I increase the font of the menu? The letters are too small right now. Thanks so much!!!

Hello,

You can go through this for more information about child theme:

https://codex.www.ads-software.com/Child_Themes

And for the font size you can try this in your Custom CSS:

.menu-top-navigation-container ul li a {
    font-size: 20px;
}

Thank you.