You have to use the Multilingual plugin on your site, if you want to translate and use your site in multiple languages, Our theme is fully compatible with the WPML and Polylang plugins, you can use any one of them as per your requirements.
To add languages to the header next to the menu use the Widgets element https://prnt.sc/1tg32en and choose the widget area you want to display. In the Appearance > Widgets > Left side top bar area > add the language switcher widget.
As I know Polylang won’t offer multiple currency options but it would be better for your to clarify that from the plugin author.
Regards 8Themes Team.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.