Hi again,

#1. Case 1: To save Home page template, please go to edit page with Elementor -> Save as Template -> Save with our template name: https://prnt.sc/vu72h2

When you want to restore template, you can insert template again.

Case 2: Use Plugin Duplicator
to backup all your website.

#2. Case 1: add code into file functions.php ( child-theme)

add_action('wp_head','my_analytics', 20);
function my_analytics() {

Case 2: Use Plugin Insert Headers and Footers, you installed it