I’m planning on going through an exchange program studying abroad in either Korea (I’m an America born Korean and I want to experience how school life is over there) or Japan (so I can learn a new language)
I don’t know much about exchange programs yet but how will it affect my current school life (thats If i don’t do it during summer) If I leave my school and return, would I have a ton of missing work or what? I know I would have the choice to do it for a whole 11 months or even 2 months so which is recommended ignoring the fees? Also, how good does studying abroad look for colleges? Is it good at all?
You need to speak to your counselor, since every school has its own policies. USUALLY the courses you would take in Korea or Japan would count on a pass/fail basis. And if you take, for example, history while studying abroad, that may count toward meeting your history/social studies high school graduation requirements. So you need to take a look at all the graduation requirements at your high school, and make sure you can meet all of them by the end of your senior year. (Your counselor will also help you with this.)
Colleges like study abroad – and like a year-long study abroad in particular – especially if you go to a non-English speaking country. Since you’re Korean, it would look better if you went to Japan: different culture & language, it shows you’re really challenging yourself.
Thank you for the response!
I have another question, in what year should I go? I’m currently a freshman so I have 3 more years left. I heard junior year is the most important so maybe going as a junior is not a good idea but I don’t think I’ll be able have enough time to save up enough money till sophomore year… As for senior year, i’ll have to do college applications unless it’s gonna be alright and I just need to do it in Japan. What do you recommend?
I wouldn’t recommend that you go in your senior year because this will probably add extra stress to the whole hectic process of college applications.
Good luck anyway! 
Students typically go Junior year (full year) or spring semester senior year.
Going for two months wouldn’t be as significant - going a full year is the best. However because school calendars aren’t the same (the year starts in March) you could probably go February-August if need be.
See how your school handles it - typically you need to estimate what classes you took (calculus, Japanese history, etc.)
Note that Koreans suffer from racism in Japan so you have to prepare mentally for that - being assumed inferior is a difficult thing.