Going to South Korea in mid-November - what should I prepare in advance or be aware of?

Hey everyone! 👋
I’m planning to visit South Korea in mid-November, and I just want to make sure I’m not missing anything important before my trip.

From what I’ve researched so far, I know I’ll probably need an eSIM and should prepare for public transportation (like downloading the right apps or getting a transportation card).

But are there any other things that might be inconvenient if I don’t prepare them in advance? Or anything that’s better to figure out after arriving in Korea?

Any tips, advice, or things you wish you’d known before visiting would be super appreciated.
Thanks in advance! 🙏