Getting started with research is sometimes the hardest part! Most likely, you'll have to do some pre-search to figure out exactly what your research topic is going to be. For your pre-search, I recommend spending some time exploring your topic(s) of interest, looking at:
Keywords are the words that you type into the search box to find resources about your topic. What are the most important words in your research question? Think of synomyms for those words.
Example: How does exercise impact the mental health of college students?
Practice: Brainstorm possible keywords for this topic:
How do mentorship programs for new teachers impact have on teacher retention?
After you have decided on your keywords, you'll need to tell the database how they should be connected.
"college students" AND exercise
Will find resources that have both college students and exercise as keywords.
"college students" OR undergraduates
Will find resources about college students OR undergraduates.
"public university" NOT "private university"
Will find resources about college students at public universities not private.
After you decide on your keywords and how they connect to each other, you should come up with a few search strategies that you'll try in the databases.