“Make visible what, without you, might never have been seen.”
You have the impulse to write, but maybe you’re not sure yet exactly what you want to write. It’s not unusual for creative people to try to do everything, preferably all at the same time. If you want to make writing a hobby, then by all means jump around and write as many different things as you like. But if you aim to be a professional writer, it makes sense to focus on one type of writing and work hard to gain expertise and success in that arena.
The easiest way to figure out what you should write is to answer this question: What do you love to read? If you devour mysteries, or haunt the bookshop waiting for the latest Stephen King and ...