Hi Nimue,
Custom CSS can be added on X > Launch > Options > On the left sidebar: click CSS . Add it there.
For adding script, we need your child theme to be active. Then we will add the code on your child theme functions.php file. Something like this:
add_action('wp_head','script_on_header');
function script_on_header() { ?>
//Add your script here. This will be added on the header
<?php }
If you’re still not comfortable doing this, we do have an in-house custom development team that offer paid services, who may be able to assist. They can be contacted at pinnacle@theme.co if this is of interest to you. If you have any further questions about the theme, we are more than happy to provide you with assistance on these inquiries.
Thank you for your understanding.