Based on the final part of the question, it seems that you are asking for help writing an introductory paragraph about “The Cask of Amontillado.” The start of that introductory paragraph is your “attention getter,” and the end of the paragraph will be your thesis statement.
The thesis is a critical part of the introductory paragraph; however, I always emphasize to students that the first sentence is equally important. The first sentence is what must grab reader attention. You can have the best thesis in the world, but if your first sentence leaves your reader bored, he/she might not even bother reading long enough to get to your thesis statement.
Since you are writing a paper about a piece of literature, I recommend one of four attention-getters.
Use a quote. This is preferably from “The Cask of Amontillado.” A quote carries extra weight and importance in the minds of most readers. Using a quote activates reader engagement because the reader believes the quote is of critical importance.
Use a definition. Preferably the definition will have something to do with your thesis statement. If your thesis is about about revenge, maybe you could define revenge.
Make a bold, perhaps controversial, statement. The goal here is to get an emotional response out of your reader. “Fired up” readers keep reading.
Ask a question. This is probably the easiest attention getter. It will guide the opening paragraph because you will hopefully answer it within the following sentences. Additionally, a question immediately forces your reader to consider possible answers to the question. That kind of reader is an engaged reader, and he/she is likely to keep reading.
To close the introductory paragraph, you will use your thesis statement. A good thesis statement is a statement that is debatable. Your paper’s goal is to prove your thesis. Saying that “The Cask of Amontillado” is a story about revenge is not a thesis. There isn’t anything to debate. I usually recommend a two-part thesis statement. The first part of the statement admits to the counterargument of the second part of the statement. You can easily start this kind of thesis with the word “although.” For example: “Although readers generally assume that Fortunato is Montresor’s first victim, it is much more likely that Montresor has killed before and will kill again.” That particular thesis allows you to closely examine Montresor’s motivations for killing Fortunato and closely examine his extremely well-executed plan.