Topics can be too broad and narrowing your scope can be difficult especially if you're unfamiliar with the nuances of your topic. You should look for ways to narrow specific aspects of your topic by doing background research.
Librarians love to help you brainstorm and find ideas; you can ask for help narrowing your topic.
Topics can be too narrow, requiring you to broaden your scope. In these cases you should look for broader topics and ideas.
Again, you can ask a librarian for assistance in broadening and expanding the search criteria.