functions.php

<?php

/* stylesheets */
function load_stylesheets()
{

    wp_register_style('bootstrap', 'https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css', array(), false, 'all');
    wp_enqueue_style('bootstrap');

    wp_register_style('style', get_template_directory_uri() . '/style/style.css', array(), false, 'all');
    wp_enqueue_style('style');

    wp_enqueue_style( 'google-fonts', 'https://fonts.googleapis.com/css?family=Poppins:400,500,700&display=swap', false );
}
add_action('wp_enqueue_scripts', 'load_stylesheets');

/*jquery*/
function include_jquery()
{
    wp_deregister_script('jquery');
    wp_enqueue_script('jquery', 'https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js','', 1,true);
}
add_action('wp_enqueue_scripts', 'include_jquery');

/*custom js*/
function loadjs(){
    wp_register_script('customjs', get_template_directory_uri() . '/js/script.js', '', 1, true);
    wp_enqueue_script('customjs');
}
add_action('wp_enqueue_scripts', 'loadjs');

/* navigation menu */
add_theme_support('menus');

register_nav_menus(

    array(
        'top-menu' => __('Event Menu', 'theme'),
        'footer-menu' => __('Footer Menu', 'theme'),
    )
);