Classic Commerce can be used in different languages. You will need to download the appropriate language pack (containing one .mo and one .po file). These files should be uploaded to the wp-content > languages folder on your website.
Language files can be downloaded here:
NOTE: The language above are based on the corresponding WooCommerce language files and some Classic Commerce translations may be missing or incorrect. To report any omissions, or for any other questions, support requests or general discussions please use the ClassicPress community forum.