This achievement is story-related and cannot be missed.
*** Spoiler - click to reveal ***After your walker incident in the shed, the cabin's residents will let you inside. You can have some kind or harsh words with Rebecca, Nick and Luke. Luke tries to welcome you while you enjoy a bowl of (rice?) at the dinner table. Following the conversation, you will head out automatically with Uncle Pete and Nick. The achievement "Headed Out" unlocks at this point.