The Nine and Sixty Ways
Not to harp on it too much, but sometimes I'm bemused by people who tell me definitely, "There are only eleven different plots." Sometimes it's nine. Sometimes it's seven. Sometimes it's three. One writer told me "There's only one plot: Joe gets his ass caught in a bear trap and has to get loose."
I don't know how many different variants of plot there are. I don't much care. In a poem called "In the Neolithic Age," Rudyard Kipling lets a would-be tribal poet (moved to violence by criticism of his work) learn the lesson "There are nine-and-sixty ways / Of constructing tribal lays, / And every single one of them is right."
What Mr. K. was saying is that each writer brings his or her own vision to the page, and within certain limits, anything goes. The limits? Comprehensibility. Cohesiveness. Communicative ability. The ability to touch a reader emotionally. If you can achieve these, your plot will serve.
Which means that your plot is a framework. It should hang together by cause and effect. You shouldn't bring in an enormous coincidence to wind things up (this is the deus ex machina ending, the "god from the machine," so called because some Greek tragic writers - I'm looking at you, Euripides - would wrap up messy plots by having an actor portraying a god lowered onto the stage by means of a machine, a windlass, and arbitrarily settle things: "He didn't kill the king, she did. Punish her, not him. Hmm. that makes him a widower. Okay, let's let him marry...um...her over there, she'll do. And, oh, yes, the kingdom is blessed now. 'Cause I'm a god, okay?").
Within the limits of being plausible and operating by cause and effect, the plot can work, can serve as the frame of your story. The timbers are the characters, their motivations, their personalities, their ability to be memorable and touching and strong.
However, a plot shouldn't have obvious holes in it (and when you get lost in your characters' lives, it's agonizingly easy to overlook a plot hole). Agatha Christie reportedly once read a mystery novel and observed that if the police had interviewed one character, someone they obviously would have questioned in real life, the mystery would have been solved in Chapter 1. She toyed with the idea and then wrote an entire novel, Why Didn't They Ask Evans? to give a plausible reason for such an oversight.
My advice? Don't worry about numbers and types of plot. Create a character. Get really interested in him or her. Give the character an enormous problem. Let the character try to solve it, only to wind up in deeper trouble.
Then go along for the ride.