One of the hardest parts of a literature review is to develop a good research question. You don't want a research question that is so broad it encompasses too many research areas, and can't be reasonably answered.
Defining your topic may require an initial review of literature on your topic to get a sense of the scope about your topic. Select a topic of interest, and do a preliminary search to see what kinds of research is being done and what is trending in that topic area. This will give you a better sense of the topic, and help you focus your research question
In specifying your topic or research question, you should think about setting appropriate limitations on the research you are seeking. Limiting, for example, by time, personnel, gender, age, location, nationality etc. results in a more focused and meaningful topic.
You may start with a general question:
Why did the chicken cross the road?
This question is so general that you could be gathering relevant research for days.
A more precise research question might be:
What are some of the environmental factors that occurred in New Jersey between January and June 2021 that would cause a chicken to cross Route 3?
This research question is specific about a number of variables like time, geography, etc.
Some questions to think about as you develop your literature review: