WP Register Menu

// Add Navigation Menu

add_action( 'after_setup_theme', 'nav_menu_function_name' );
function nav_menu_function_name() {
    register_nav_menus( array(
        'header_menu' => 'Theme Header Menu',
        'footer_menu' => 'Theme Footer Menu',
    ) );
}

// Displaying Menu in header.php

wp_nav_menu( array(
    'theme_location' => 'header_menu',
    'container_class' => 'menu_class',
    'container'       => 'div',
    'container_class' => 'class-name',
    'container_id'    => 'id-name',
    'menu_class'      => 'menu-class',
    'menu_id'         => 'menu-id',
) );