If I need to change the theme in a few years, how should I update it?

Hi juneba588,

Thanks for reaching to us.

I highly recommend you to take a complete backup of your site before proceeding.

Or create a devsite – also called a Staging platform where you can test issues, enable/disable features/plugins thus such changes will affect the main site. The below article will help you to create it:

https://www.wpbeginner.com/wp-tutorials/how-to-create-staging-environment-for-a-wordpress-site/

Please refer to our detailed article https://xtemos.com/docs-topic/update-the-theme/

Regards,