Research is a process! Try one search and evaluate your results. If necessary, modify your strategy (use different keywords, try using the Boolean operators, etc.) and try again.
Use the different limits available in most databases to help narrow down your results. Of course, if you're not getting enough results, you may need to broaden your search term(s) or select fewer limits.
Some examples of limits are:
Angie, Locke. Fishing for Information. 2015, Wikimedia Commons. commons.wikimedia.org/wiki/File:Fishing_for_Information_Research_Infographic.png. This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.