Here are ways I am preparing for my study abroad (including updated tips from after arrival):
Prior to leaving, my friends and I decided to live in a goshiwon. We booked it online after narrowing our choices down using https://goshipages.com. Find more information on our housing in the blog after this one!
For packing, I brought two suitcases and fit one inside of the other.
*NOTE: I just returned from Korea and regret not bringing more suitcases. My friends and I each had FOUR full suitcases when returning. I highly recommend bringing at least three suitcases to Korea (fit the smaller one inside of the larger one).
I also had to acquire a D-2 student visa at the Korean embassy prior to studying abroad by filling out the forms at the embassy and bringing all the required information. It took about three weeks to receive my student visa. You can find information about applying on this website: https://overseas.mofa.go.kr/us-honolulu-en/wpge/m_5539/contents.do
Some of the forms online are outdated, so when you arrive at the consulate, you can find updated copies on the desk over there to fill out. They also have a computer you can use if you need to print anything out.
Also, I cannot stress this enough. PACK LIGHT. Do not bring your whole wardrobe. And if you're studying abroad in the Fall like me, it's gonna be really hot when you get here. I recommend bringing a mini portable fan or buying some while you're here because the heat can really hit you!