Don’t make these mistakes before attending a Korean university

Have you ever wanted to travel to Korea to study Korean before? I got to interview a friend who's currently studying at Yonsei University, and asked him about how he got to where he is, how he's been studying Korean and the mistakes and challenges that he's faced, as well as his advice for people interested in following the same path.

Also we met up in November and the weather was obviously a lot nicer then than it is now there (it's really cold and snowing).