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.
I’d seriously worry about not having immunity to whatever diseases exist in that world, and the people of that new world not having immunity to whatever I might be carrying from my world.
Probably try and figure what the skills of the other survivors on the train to assemble a team with the goal of survival and information gathering.