I have always found Koreans, underneath a certain surface brusqueness, to be warm, kind, welcoming and friendly people. You will not be expected to know the details of, say, bowing or serving tea. Do what comes naturally to you -- often a small bow or nod and smile. Be polite in American and you will be fine. Do not be afraid to ask! "Please show me how to do this properly" or even, "tell me what would be the polite thing to do (here, in Korean culture, etc.)" work well for me in cultures foreign to me. It is also fine to say, "in this situation, an American would normally do this. What would a polite (whatever) do?" People appreciate it when you try, and like it when you want to learn. Remember, they want to learn American ways, too! This will help you make friends, to the benefit of all concerned. There will be lots of fun as the kids teach yours impolite things in Korean, and everybody will laugh, he'll learn some Korean, and all will be well.