Understanding the difference between plot and story is critical to your success as a writer. The plot moves the story. The story makes the plot more interesting.
Using passive voice is an oft-cited faux pas for writers.
Before I get into what it is and how to correct it, I want to be clear: Passive voice is not a bad thing. Don't listen to grammar pedants who tell you otherwise. It's better to use active voice in many writing situations. This post addresses situations when active voice is better than passive and why.