If you can provide cpanel access I can do the necessary backup.
It’s ALWAYS recommended to do a backup when making changes like this.
Updating the theme should not delete an of your data but it’s better to be safe than sorry.
Also, in version 1.0 the content sections (About, Services, Contact text) are edited in the Options Panel. In the new version it’s done thru pages. So whatever content you have in there you will need to migrate to a page. Which is why it’s probably better to install a fresh version, migrate your content then change the URL.