After creating your character, enjoy a brief moment of calm and domesticity by drinking your morning coffee and saying hello to your son in his crib. This will trigger a visit from the Vault-Tec representative.
You can say no to the Vault-Tec rep, but your spouse will convince you to sign the paperwork just to get the process over with. Eventually, air raid sirens will blare, triggering the evacuation.
You can talk to the anxious neighbors and explore, but you'll quickly run out of things to do before settling for refuge in Vault 111. There's also nothing of value in the cul-de-sac to the left of your house, and if you go right and follow the road out of suburbia, you will be vaporized.