How to effectively learn Korean while studying in Seoul for two months?

Hello! I recently finished my studies and would like to go to Seoul for two months to learn Korean as a reward. I took a Korean class four years ago and stayed in Seoul as an exchange student during that time. However, it seems that I have forgotten most of what I learned over the years. I want to make the most of this opportunity and rebuild my foundation. Can I join Winther's A1 class? I would appreciate any advice on how to learn Korean quickly. Also, I want to interact with people, but I'm quite introverted and don't know how to start. Do you have any tips or methods for meeting new people in Seoul? I need help. 🙈