Fortunately, eNotes has ample coverage on "The Interlopers" by Saki. If you click on the reference links below, you will get to the Study Guide with access to a summary of the story, characters, themes, criticism, and many other features. If you click on Q@A in the Study Guide for Saki's story, you will see that there are 144 questions that have been answered about this one short story. The Introduction in the Study Guide will give you some basic information which ought to help prepare you for what will be asked on your exam.
The best way to analyze a story is to ask Who wants what? Whose is the motivation that drives the story? The conflict is caused by someone or some thing thwarting that motivation. I think you'll find that the irony in this story is very obvious, as is the central conflict.