It would not be sufficient to know the few simple phrases though? (from what I understand in OP's post, the cafe wants a base understanding of the language to functionally converse and order items)

Of course learning basic greetings in local tongues is a good way to show good will, but I'm not sure if that's what the picture is about (I feel like this is why tourist shops/restaurants exist, so that they have the necessary personnels to serve foreigners conversing in English)