Obviously, to write you need story ideas. These can come from anywhere, at anytime. Yes, that includes school, and not just in writing-related classes like English.
For example, in French class we were reviewing train station vocabulary. My teacher explained that the term meaning “waiting room” was somewhat misleading because most people didn’t actually wait there, since they can’t tell if their train is coming from that room. Most people wait for their train on the platform so they don’t miss it, unless they have several hours before their train arrives. Surprisingly, this sparked a shred of an idea. I wrote in my binder the line: We waited for the train for three hours, and we missed it. Now, it’s not much, I know. But it could turn into something. Why were you waiting for three hours? What caused you to miss it, if you were there so early? How important was it that you made it on the train? Where was the train going? See? It doesn’t take much.
Things like this have also happened in math. I’ve never been a math-minded person. It’s never been what I enjoy at school. But recently, my teacher has been saying things (normal, math-related things) that have given me ideas for a story. A lot of getting story ideas is taking something (e.g. something your math teacher said) and asking questions. Questions like what if? Take something normal, and change it. Make it the opposite and see what happens. Expand on it. Make it important.
History is a great class for story ideas, if those are the types of stories you like to write. History classes and textbooks often seem to focus on what happened, when, who was involved, and the significance and impact of the event. These things are important, for sure. But what if you considered how the people involved felt about what was happening? What was everyday life like? How was it for adults, teenagers, children? What would be different about your life if you lived in a different period of history? Make a story out of that.
In fact, I would challenge you to pay extra attention in all your classes, and try to get even just a shred of an idea from every class. Allow yourself to be inspired by even the most mundane things. Listen carefully. Take things you hear or read or see and expand on them, think about what would make them interesting. My idea about the train isn’t very interesting if they were just going to the next town to shop for clothes. But what if they were going to visit a very sick grandmother in the hospital, or to an underground meeting of a secret agency? Suddenly the story gets a lot more interesting. Give those shreds of ideas meaning.
How do you get ideas? Has school ever inspired you?