Get a working knowledge of your topic.
You could just use Google, but...
As you are Googling and consulting general, less authoritative sources (Wikipedia), you may realize your sources are all taking the same position on your subject and often cite the same people.
Relying on just Google and online encyclopedias risks an echo-chamber effect of a tight circle of sources citing each other without much verification or original research. Expanding your search to include relevant original research from more than one resource will shed light on the true complexity of the question.
Now it is time to decide what you already know and what you want to know about the topic. This will allow you to formulate a good research question. Good research questions are:
Sample Question: What is the effect of screen time on developing brains?
Break down your research question into main concepts. Then think of keywords you can use - as well as synonyms for them - in your search.
Question: What is the effect of screen time on developing brains?
effects "screen time" "developing brains" adolescents "young adults" streaming "watch time"
(Notice I put phrases in quotations. This tells the databases to search those words in that exact order.)
Now let's run the search!