Keeping Templates and Settings

I’m using an extremely outdated version of Enfold (2.0) for a client website. I made all the customization on the custom.css and the functions.php file within the original Enfold folder (not the child theme).

I need to update the theme badly using the Enfold Child theme. How do I make sure the templates and settings are carried over?

Here are my worries:
1. All the pages have been built with the Avia Template Builder. Will the page structures remain?
2. Templates saved in the template builder, will they carry over? Do I need to export and import these settings?
3. All the settings, do I need to export and import those as well?
4. Is all this saved in the database of within the theme preferences?

I don’t want to lose all the templates when I install the Enfold Child theme and update the original.

Thanks for any help.