A little homework beginning now can lessen the language barrier. You will not find sweetened iced tea. In fact, you may not even find iced tea. There is nothing in their culture even remotely resembling grits. It is usually not spicy, but it is more highly seasoned than average American food.
Greek cooks use a lot of garlic, thyme, oregano, rosemary, and mint.
Meat is common, usually beef or pork but occasionally lamb and sometimes goat. Seafood is prevalent and among the finest in the world. Vegetarians may at first find it difficult to explain that they don't want meat. Usually meals feature plenty of fruits, vegetables, and breads, so even if meat is a featured part of a meal, there is more than enough to satisfy most appetites. Remember, breakfast and lunch are included in the trip cost.