Hi, Julia,
I was “motivated” by a burning desire to pass 7th grade English! The story that became my first book started as an English assignment to write what our teacher called “a novelette.” As you can tell, I got carried away and wrote a long tale.
As for a topic, it’s VERY important that the topic must come from you. You will do a much better job if you’re writing about your own idea, something that interests you. As a matter of fact, my first rule of novel writing is that you never write a single word until your story is well-planned first. You can’t say anything properly unless you know exactly what you’re trying to say. And you can’t know that unless you plan.
Happy writing! —-GK—-