Sorry for the delay.
First you need to create a new sidebar for the header so you’ll need to add this to functions.php (if you don’t want to use a plugin) …
function header_widgets_init() {
register_sidebar(array(
'name' => esc_html('Header'),
'id' => 'sidebar-3',
'description' => esc_html('Add widgets here to appear above your header.'),
'before_title' => '<h2 class="widget-title">',
'after_title' => '</h2>',
'before_widget' => '<section id="%1$s" class="widget %2$s">',
'after_widget' => '</section>'
));
}
add_action('widgets_init', 'header_widgets_init');
Then (if you really don’t want to use a plugin or a child theme which we really don’t recommend) in /template-parts/header/site-header.php you will need to add this on line 17 after the <header>
element …
if (is_active_sidebar('sidebar-3')) {
?>
<aside id="header-sidebar" class="widget-area">
<?php dynamic_sidebar('sidebar-3'); ?>
</aside>
<?php
}
That will allow you to add widgets at the top of your header. Obviously you’ll need to style the widgets to look the way you want them to … will you need help with that?
If you would prefer it to be a menu then you can create another menu location instead. Let me know if you’d prefer that and I’ll give you the code although a widget area is more flexible and you can use a Navigation Menu widget to show a menu anyway.
Hope that helps?
Oliver