Hello. I live in Busan and travel to Seoul every week for business. Of course, I bring my racket. There are more clubs in Seoul than you might think—hundreds, perhaps. Furthermore, Seoul is so vast that it's best to minimize travel time. I work near Gimpo Airport in Seoul, although not every day. Knowing your accommodation location will help us make recommendations. Seoul is so large. It takes over an hour and a half to travel from one side to the other.
If you leave your SNS messenger or contact information, I will contact you. If it fits my schedule, I can help you directly. First, search my article and refer to how to play table tennis in Busan.
Because league matches are broadcast across various social media platforms and regions, there's no single, centralized site. This is especially true in Seoul. Fortunately, I've subscribed to several sites and have even attended league matches in Seoul. If you'd like, I can share information about league matches worth joining. League matches are usually held on specific days at each site, and tickets tend to sell out quickly.
Korea has a special handicap system for players of different levels. It's usually divided into eight divisions, with lower levels representing higher levels. For example, if a level 5 player plays a level 6 player, the level 6 player starts with one point for each game. The maximum handicap is six points. For women, two points are awarded to players of the same level (in Busan, it's 3points). Your usatt score of 2100 is considered quite high, and would likely be equivalent to level 2 or 3 in Korea. If you say you are level 3 while playing in Korea, your opponent will apply a handicap system based on their level. Most table tennis clubs have a maximum level of level 3 or 4. Therefore, if you want to meet high-level players, it's better to get help than just visiting a random club.