create menu scroll for onepage Theme

Hello everyone,
i have create onpage Theme with wordpress Function Reference/get pages
below the code

<?php get_header();

	// define how pages will display
	$args = array(
		'sort_order' => 'ASC',
		'sort_column' => 'menu_order', //post_title
		'hierarchical' => 1,
		'exclude' => '',
		'child_of' => 2,
		'parent' => -1,
		'exclude_tree' => '',
		'number' => '',
		'offset' => 0,
		'post_type' => 'page',
		"post_parent" => get_the_ID(),
		'post_status' => 'publish'

	);

	$pages = get_pages($args);
//start loop
foreach ($pages as $page_data) {
    $content = apply_filters('the_content', $page_data->post_content);
    $title = $page_data->post_title;
    $slug = $page_data->post_name;
?>

<main role="main">

	<section><!-- section -->

		<div class='<?php echo "$slug" ?>'>
			<h1><?php echo "$title" ?></h1>
			    <?php echo "$content" ?>
		</div>
	</section><!-- /section -->
</main>

<?php
}
get_footer();
?>

now i need to create the menu scrollable for all page,
someone can tell me how can do it without installing plugin?