@Uchigawa_ni_shinda17 Hmm, writing during English class and writing novels to satisfy your own passion is very different in a sense that one is quite rigid (the requirements to follow a certain writing patterns, the objectives to score a high points, the given topic which might not suit your preferred genre, and not to mention the time constraint), whereas writing for your own passion has none of those rules.
By constantly reading, writing, editing and asking for critics to critique your work, you will, in time, find yourself improving so much when you read back at your old stories, you'll be surprised. Very surprised that there's so much room for improvement.