If you can't come up with an original plagiarism of one of the existing formulas of story tropes, there are old stories that do not even have copyright.
Hansel and Gretel - You have betrayal there. Exploration. Food theft. Danger. A fight against evil with your wits instead of brawn. Cooking recipes. Plenty of opportunity to add interactivity to this old story.
Ever wonder why there is a gazillion rpgs and somehow they are all the same? It is because they are. Same for drama movies. There are only a few base concepts where you exchange names and places and plot devices.
Search the net for Avatar is Pocahontas.
Or think creatur horror movies. There is no fundamental difference between those slasher movies with people in a remote cabin in the woods and a monster chasing them and the movie Alien (1979).
So basically, copy something you like and give it your own spin. Since you were exposed to fiction for years, it is practically impossible to generate any kind of original content that is not inspired or influence by something that already exists. And even if you tried to and succeeded, your story could be bend to fit an existing narrative. It is a bit like grammar. To even be a story, it has to follow rules. Same as words have to follow rules to make a sentence or else be gibberish.
While I make it sound as if writing were easy, of course it ain't. It is the details and the execution, that is hard. Coming up with motives and telling the story in a way that is interesting.