Create a bootstrap folder and copy paste all the files in your child theme directory
/wp-content/themes/theme-child/bootstrap
Edit functions.php and include the following inside function theme_child_enqueue_styles()
wp_enqueue_style('bootstrap', get_stylesheet_directory_uri() . '/bootstrap/css/bootstrap.min.css');
wp_enqueue_script('bootstrap',get_stylesheet_directory_uri() . '/bootstrap/js/bootstrap.min.js');
That's it. Inspect page for errors.
