How did Sam get the first fish he caught cooked and learn how to start a fire?

Sam wasn't able to start a fire after he caught his fish. He spent a miserable night in his shelter, and then in the morning he went down to the road. There he saw a house, knocked, and asked the old man there if he could cook his fish. The old man cooked the fish for him and fed him other food. Then the man, named Bill, took Sam outside and taught him how to make a fire with flint and steel.