In our theme you you have 3 options to use language switcher.
In Main menu
To show the language switcher in the Menu go to WPML → Languages → Language switcher in the WP Menu and select menu that is your Main menu(in header location).
In top bar
If you are using horizontal theme header, then there is special place in top bar for language switcher.
You can also use WPML widget and place language switcher in any sidebar you want.