Once you are done talking to Clementine, you will have your first major decision to make; whether to leave the house in the day or the night. If you choose to go in the day, you will run into Shawn and Chet in the street and you will need to help them move a car out of the way to get their truck free.
If you choose to go at night, you will run into Shawn and Officer Mitchel, along with zombie Chet who doesn’t make it home for hot dish night. If you choose the night route, there’s less to do than in the day option and when you reach the farm, the dialogue between Shawn and Hershel about fortifying the fence is different. Hershel will say that since Chet is dead, it’s a good idea to do it, whereas if you choose the day route, Hershel doesn’t think it needs to be done, but still agrees to it.
When you talk to Shawn in both the day and night scenarios, the dialogue option that you choose to tell Shawn about you (Babysitter, neighbor, just a guy, or if you say nothing, he will call you a good Samaritan) will affect what he tells Hershel when you arrive at the farm, and the one liner that he makes when you are driving away from the front of Clementine’s house.