Edit: apparently this is a very common form of Japanese storytelling called an isekai. There are 8 billion people in this world, no idea can be original. And sometimes you miss out on things many other people know. I’m clearly one of today’s lucky 10000.
Probably just sit and wait for what happens next and hope all the people around me don’t freak out.
I lived in Japan for years without knowing about the whole isekai thing; I’ve just never really been into anime/manga.