You can create fully functional multilingual site using one of the popular multilingual plugins supported by Arrigo theme. Those are WPML (powerful all-in-one paid plugin) and Polylang (lightweight alternative available for free).
When one of these plugins is setup and activated you will see a new widget area for the language switcher.
Language switcher is customizable. You can choose it to appear as dropdown or horizontal list. While the theme provides some styling for the switcher, all the customizations are available inside multi-lingual plugins settings.