Thats great amelia, having an open mind to different ethnicities and languages is a great way to integrate yourself with the locals of another country. I would like to offer some help but i'm too busy to meet in person.
So ill just give some random advice.
You are Asian and should generally not stand out from the locals, so don't feel like an alien because you don not look like one
and get anxious by worrying yourself, just be cool around people and make yourself appear friendly and people will generally be attracted to you.
The locals generally speak a funny spin of english called singlish which is a mixture of chinese and english, so dont be surprised to hear people ending their sentences with "lah or leh". Its just the local lingo, every country has its own. Try to learn it by watching youtube videos and ditch your korean accent, i know this may come across(i hope not) as arrogant of me but i just want to help. LOCALS DO NOT REACT WELL TO FOREIGN ACCENTS, not to say everyone will shun you but it will make you stand out as the "foreigner" which depending on where you are from is associated with different disadvantages if you want to make friends.
Be observant and look out for the style that other girls at school dress in and try to copy it, aka wear clothes similar to what the others are wearing.
Now the thing about korean ladies;) If you are looking for a boyfriend, your in luck! There is a somewhat high opinion of korean culture and female korean singers that local males for being pretty and exotic. Just the fact that you are of korean nationality already brings you a cut above local girls in the dating game.
Best wishes
Just bring out your books to study and read!