Hi there,
Thanks for writing in! Once you setup a child theme, you can find the style.css file on your child theme folder.
To add Javascript scripts, you can add the following code into your functions.php in your child theme.
function my_javascripts() {
<!--Add Your Javascript Below this line-->
<script type="text/javascript" src="path.to/your/javascript.js"></script>
<!--Do not modify anything below this line-->
<?php
}
add_action('wp_footer','my_javascripts');
Hope that helps.