This code will load other style.css files and js scripts. Place this code in the functions.php file in your child theme directory.

Enqueue other styles and scripts

<?php

add_action( 'wp_enqueue_scripts', 'my_assets' );

function my_assets() {
	wp_enqueue_style( 'parent-theme-css', get_template_directory_uri() . '/style.css' );
	wp_enqueue_style( 'fancy-box-css', get_stylesheet_directory_uri() . '/css/jquery.fancybox.css' );
    wp_enqueue_script( 'fancy-box-script', get_stylesheet_directory_uri() . '/js/jquery.fancybox.js', array( 'jquery' ) );
}