What is life like as a Korean-American student in Korea?

I am currently a first-year high school student and I plan to move to Korea this summer. I am planning to attend an international school from the second year of high school in Korea until graduation, and I am curious about what life in Korea will be like as an international student. Although I am fluent in Korean, I am worried because I do not know much about school life or culture in Korea. What should I expect while living as an international student in Korea? I am especially curious about life in areas like Gangnam or Hongdae, and I would like to know what is important in terms of academics and making friends. There may be various cultural differences such as the unique housing types in Korea like jeonse or monthly rent, officetels, so I would appreciate any advice on this.