It's been said before, but the usage of 인증 and cell phones is jarring, even for Koreans. For 외국인 it's harder because most of the process is recursive. You need a cell phone to 인증 but need an 인증 to get a real (non temporary) cell phone number. Most banks and official things like cell phone plans will need fluent Korean. Have friends or an advisor help you unless youre at TOPIK 5 or 6. Maybe it's gotten better since COVID? you need to learn nunchi. If you're outgoing? Be less. If youre not? Be more social. It changes all the time. You can't really express a scientific opinion that is unique even if you have evidence for it, the culture that ive seen is very much "go with what is current and acceptable".