1. Babochorum
Babochorum consists of "Babo" and "Chorum". The former is a noun which has similar to "an incredible jerk" in English, and the latter is an adjective similar to "like" used in "like someone/something". The literal meaning of Babochorum is "just like an incredible jerk".
However this words can be used in an aronic situation. You can use this words to close people in order to indicate your concern, gratitude or your positive evaluation for something that they have done
2. I don't know
If you want to say I don't know in Korean language, you may say one of them shown below:
1) to close people to whom you don't need to show your respect,
you may say : 잘 몰라요
2) to people to whom you need to show your respect somehow,
you may say : 잘 모르겠어요, 잘 모르는데요, or 잘 모르겠습니다.
I hope there will be better answers than mine.