Unfortunately, only the social menu location and the search bar is in that spot. To add anything new there, you will need to use a child theme and modify the theme file containers in that area. The pro version has a sidebar for widgets to the left of that, but because you are using the free version, you will need to edit the theme.
Another option would be a plugin that lets a visitor choose the language, but one that has a floating language option box (I don’t know of one off hand). I think there is a plugin or method that you can add to the main menu though…if you are using a plugin for selecting different languages, perhaps the plugin author might be able to help with that option. Otherwise, the only other option I can think of is to use an existing sidebar position to load a language selection widget.
As an aexample, if you are using Polylang, it appears you can add a language selector to a menu (custom menu). If you are using a different plugin, contact the developer and see if you can do that.