I presume that you are referring to the start of chapter 3: Huts on the beach where Jack is alone in the forest. The answer is that Jack is trying to hunt pigs.
pig
setting the forest on fire
Ralph opposes Jack's violent ways. He also trying to stop the boys approaching Jack's view of the boys. Moreover, by hunting Ralph, Jack is trying to show who the real leader is and why everyone should follow him.
Ralph and Piggy join in Jack his tribe's dance during the night when Simon came out of the forest. Jack and everybody else thought he was the beastie (since it was so dark) and they killed him.
I presume that you are referring to the start of chapter 3: Huts on the beach where Jack is alone in the forest. The answer is that Jack is trying to hunt pigs.
In Chapter 4 of Jack and the Beanstalk, Jack goes to the forest alone to sell his cow.
in the forest
bease the forest cover ivaesw
They are practically just solutions trying to solve forest fires
Jack asks for food, specifically something to eat and drink, as he is very hungry and thirsty after his time in the forest.
Ralph
pig
When Jack comes out of the forest in Chapter 3 of the story, the first thing he asks for is a glass of water.
Jack Morrish has written: 'The future of forestry' -- subject(s): Forest policy
Jack Trudeau was born on September 9, 1962, in Forest Lake, Minnesota, USA.
setting the forest on fire