"I am ashamed ... "

Hmmm. I hoped it is not due to anything I have said, as I do not understand why you would say this. My limited understanding of southeast Asian culture, though, would indicate to me this is very important to you. If I have offended you in some way, please feel free to let me know.

"... but I do not know the concept and usage of cryptocurrency and blockchain.
I don't even know how to buy and sell cryptocurrency in Korean funds and markets."

From my cultural perspective, this is pretty simple. You have just not chosen to invest the time into learning about it. No one can be proficient doing anything until they have invested the necessary time and effort.

I have always been willing to help you. You have asked for help. If you want to move forward, I am still willing to help you. Just let me know and we'll take it step-by-step.

My only caveat in this offer is I do not want to be responsible for whatever my happen with any money you would choose to invest. You need to understand "going in" that the crypto markets are very volatile. Probably not a good place for anyone faint-hearted to venture ... Even then, the best advice is just not invest more than you can afford to lose ...

Only you can say whether this is a good idea for you to proceed with or not. Let me know!