Hello,
1/ Translation files of the theme should be placed in /wp-content/languages/themes/ folder,
plugins, like core plugin, in /wp-content/languages/plugins folder.
We would recommend doing a backup of all the files before any update.
2/ Translation of XStore Core plugin – https://xstore.helpscoutdocs.com/article/30-base-theme-translation
3/ Theme Options > WooCommerce > Cart page > Empty cart content > edit content of Text tab
Regards