This code will load your child theme style.css file. Place this code in your child themes functions.php to Enqueue Child Theme.

Enqueue Child Theme

<?php

add_action( 'wp_enqueue_scripts', 'my_child_theme_scripts' );
function my_child_theme_scripts() {
    wp_enqueue_style( 'parent-theme-css', get_template_directory_uri() . '/style.css' );
}