We recommend backing up your theme before making any significant theme-related changes or before switching from one theme to another.
Backing it up will help you restore it or keep it saved in your computer if something goes wrong or a change ended up not being the best decision.
To back it up, navigate to Customization, click Backups, then select Create Backup.
NOTE: Theme backups include all theme-related elements. This excludes Navigation, Assets, and Pages, which will remain in place regardless of the theme selected.