Theatre is all about opening the audience up to things that they wouldn't necessarily experience in their own lives. You might relate to a situation on a play or a skit but there's a good chance that there are some situations that are different from your life as well. Sometimes you might get to step into the life of the Native in Canada and others might be about Royalty long ago. Almost anything can be put into a play with the right dramatic elements.
The thing that makes a play interesting is that there is a conflict that will intrigue the audience. There needs to be some twists and turns along the way in order to do that. But, that is really the only rule when it comes to creating a theatre experience. You could base it on a newsletter that turns into a gossip column or on a sports team that's about to plan the biggest game of their careers. You just need to make sure that you have enough to tell for it to compel people for the length of the show.
The other element that every play has is characters. If you've got a scene where people are at a lesson in Chicago than you're going to need to have someone in the play who is portraying the leader of the class and people as students. But, you're going to want to limit the characters to those that move the plot along. Anyone else is just going to confuse your audience or get them distracted from what they should be paying attention to. This is one of the reasons that the cast lists for plays are usually quite short. You might have a scene about an elicit affair and only include the husband or the wife in the scene.
There are many different theatre performances out there and not all are two-hour long plays. If you've got something to say in short form than you might want to put it in a skit. You can see skits in one-act play festivals or in the form of comedy sketches. Some people living in Tulsa to those in Texas watch sketches every Saturday night on Saturday Night Live, for example. This is usually more about getting one thought or idea across rather than a full story.
With all of the plays and skits out there, it is certain that there is one for anyone. You might not think that you're a theatre person but that might mean that you haven't exposed yourself to the right plays or theatre companies. Some prefer the kitchen sink drama while others like the mega musical.
Playing a role when you have no experience with the subject can be difficult which is why many an actor will shadow a person who works the job or has the skill. If you want to portray a wire rope sheaves line worker, you need to work alongside a factory employee. If you want to portray an airline pilot study the day to day tasks of a real pilot to be authentic.