Play the Overseer’s Recording
After getting your Pip-Boy, you can get ready to leave Vault 76 – but first you have to play the holotape left to you by the Overseer. Open the door next to the place where you picked up the Pip-Boy and then follow the cardboard images of Vault-Boy.
After you go downstairs, go across the field and along the corridor. On the way, you’ll go past a few Vault-Boys. You don’t have to stop anywhere, as Vault 76 contains absolutely no useful stuff.
At the end of the corridor, you’ll find a room with a terminal. Use it and choose the option to play the holotape. You’ll hear a story introduction to the game.