If you keep detailed notes through brainstorming, formulating research questions, selecting sources and beyond, you can easily go back and tweak your topic if you need to.
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After you've selected some research questions from your brainstorming session, choose one or two that seem the most interesting and will give you enough to write about. Once you get further along in the process you will know whether the questions you've chosen will work. If you find way too many resources, or too few, you may need to go back and choose another set of questions to research.
Creating your research question - This is a YouTube video, by ostrowj1, which explains the process of developing a good research question.
Developing a research question - A video from a Research Methods course by Dr. Sam Fiala.