<?php

add_action('wp_enqueue_scripts', 'my_theme_enqueue_styles');

function my_theme_enqueue_styles()
{
    wp_enqueue_style('parent-style', get_template_directory_uri() . '/style.css');
    wp_enqueue_style('child-style', get_stylesheet_directory_uri() . '/style.css', array('parent-style'));
    wp_enqueue_script('custom-script', get_stylesheet_directory_uri() . '/path/to/script.js', '', '', true );
}