When you order some food we just say (name of food - number - counter(like 개, 그릇...) - 주세요) . When you order multiple items, you just add one more thing which is 하고. so (name of food - number - counter 하고 name of food - number - counter 하고... etc 주세요)

You can use: A하고 B 주세요 (Please give me A and B.) A하고 B 원합니다. (I want A and B.) I think that the simplest way to order something. :) As you can see 하고 means "and", and it's attached to the previous noun. If you want more, basically you're going to say, "Please give me A, B, C, D, E, and F" So you could say, "A하고 B하고 C하고 D하고 E하고 F 주세요." You can replace "하고" with "랑/이랑". Use 이랑 if the noun ended in consonant, otherwise use 랑. ex: 우유랑 빵이랑 치킨 주세요. (Please give me milk and bread and chiken.) ps. That's as far as I know. If there's more simple way to order several items at once please let me know too! ^^