What does Jack's behavior in chapter 2 suggest about him, and in what ways might the behavior of the boys during the meeting foreshadow later events?

Jack’s latent violence and competition with Ralph is apparent from the start of the meeting, when he interrupts to talk about the need for an army to hunt pigs. When reminded that a pig got away from him, Jack violently slams his knife into a tree, saying “‘Next time!’” to show them all he’s not afraid to kill. The challenging look he gives them in this moment reveals the deep-seated insecurity Jack carries, and also his shame for feeling this way. Jack is the kind of person who feels that if he doesn’t have all the attention and all the control, he has none at all.
Jack’s willingness to inflict pain on others is hinted at when he suggests that they should punish anyone who breaks their rules. He is conspicuously silent when the little ‘un needs reassurance about the “beastie,” yet he pipes up at the end, saying if there was a beast, they’d hunt and kill it. Jack’s preoccupation with violence and need for excitement are clear. His continual undermining of Ralph’s authority go hand-in-hand with this, since his statement (hunting the beast) negates Ralph’s attempt to assure them that there is no beast. The final time he interrupts Ralph is when he shouts for them all to follow him to make a fire on the mountain. It’s Ralph’s idea, but before he can express an intelligent plan, Jack takes over the exciting activity.
The fact that all the boys so easily follow Jack any time he brings up something exciting or fearsome definitely foreshadows what is to come in the novel. These boys are seeking a distraction from their true inner fear—that no one will rescue them and they’ll be here until they die. Ralph’s rule-following ways and talk of rescue are a constant reminder of that fear, while Jack offers escapism and excitement of a different sort. Their collective failure to intercede when Jack hits Piggy and breaks his glasses solidify our realization that they will follow Jack unquestioningly, which indeed they do.

In chapter 2, Jack begins to display his domineering, disruptive behavior by interrupting Ralph's speech and unceremoniously ending the assembly as soon as Ralph mentions a signal fire. At the beginning of the assembly, Jack interrupts Ralph by insisting that he lead the group of hunters. Jack is also enthusiastic about punishing individuals who break the rules, which indicates that he enjoys brutality and foreshadows his violent nature. Ralph then mentions that the boys should build a signal fire, and Jack immediately tells the boys to follow him. The boys disregard the remainder of Ralph's speech and follow Jack. The fact that the boys dismiss Ralph in favor of following Jack foreshadows Jack's rise to leader of the group. Later in the novel, Jack will successfully establish his own tribe of savages who follow his directives and oppose Ralph. Jack then forcefully removes Piggy's glasses to start a fire and gets into a heated argument with him. Jack even mentions that the conch does not count on top of the mountain. Jack's violent behavior and antagonistic attitude directed at Piggy foreshadows their future conflicts. Jack's comment regarding the conch also foreshadows his dismissal of the conch and refusal to obey it later in the novel.