I'm fairly certain it's person versus person and person versus environment. I'll give a brief explanation:
Person versus Person conflict: a struggle between one person and another person -- In your case, the pistol shots and their relationship to people develops the inference that one person is shooting another person. Therefore, the person is in a literal conflict with another person.
Person versus Environment conflict: a struggle between a person and a force of nature -- In this passage, the narrator mentions that the environment is not suited for humans. The ruggedness and the difficulty of living in such an environment would thereby be a conflict to the people within it. Therefore a struggle between man and his environment.
The other conflicts:
Person versus Society conflict: a struggle between a person and a group of individuals (a social group/society)
Person versus Self conflict: a struggle between a person and the way that they think about themselves (can also be the perception others have with them or the way they think about themselves)
These are the two types of conflict that we can infer from the passage.
The first type of conflict is that of person vs. environment. Person vs. environment in this passage is exemplified by the description of the terrain. We learn that the jungle is "snarled" and "ragged," and we also learn that the protagonist calls it "forbidding." This shows that there is an opposition between the two.
The second type of conflict is that of person vs. person. This type of conflict is exemplified by the description of the men shooting pistols. The men are describes as hostile in opposition to other men.
This scene occurs after Gatsby's party showing that everyone was so drunk and in the moment. feeling like they are better than everyone else and not caring
