You start with a small introduction. It's almost completely a movie which introduces you with characters and the circumstances of the events that will occur soon. Walk towards the double door as Beth. This will make her walk out on the floor. After that, during a cutscene, you will run outside behind your sister.
You have few action sequences and path selections (risky but fast or careful) to complete. This will help you learn the mechanism that will occur in further parts of the game. After a moment you will find the first totem - death totem #1. It will show you the possibility of the death of the character that found it. Follow the tutorial instructions. No matter what you will do, it will end with the death of both sisters (it's a constant story element).