Hi~ If you plan on going to Korea for study or vacation, here are a few words for your knowledge.

Coke (Coca Cola) / Soda = 콜라 (kol-la)

They don't say Coke or Soda or Pop. They say "Kol-la". If you say "Coke" or "Soda" they might go "what?". It depends on who you talk to, though. If your server is an older lady... she's not gonna know what Coke is. 

Sprite (lemon-lime flavor soda) = 사이다 (sai-da)

Sprite is just a brand in Korea. They have their own lemon-lime flavor soda. If you want that, you say "sai-da". Spelled in English it's "Cider".

Take-out = 포장 (po-jang)

I remember I once went to a Burger King in Seoul and I told them to "Take out" but they didn't understand me. When I said "Po-jang" they understood right away. Haha!

BONUS: Please make it to go / Take out please = 포장 해주세요 (po-jang he-ju-se-yo)

The next one is a phrase the server or waiter or counter staff will ASK you

Are you dining in? "드시고 가세요?" (deu-shi-go ga-se-yo?) 

You can answer with either Yes (네 ne) or No (아니오 a-ni-yo)

I hope these were useful ! ^_____^ I will probably share more soon!