Most library databases have filters that will let you limit your search to only peer-reviewed scholarship.
As a basic example search, use Article Quick Search, on the library's home page.
At the left of the results page, click peer reviewed, as below:
Some sources which are not peer reviewed are still trustworthy. Websites produced by well known entities, such as state and federal government, America Cancer Society, Smithsonian, National Center for Education Research, (a government body), Education Weekly, are reliable.
A rule of thumb if a source is unknown, is to discover who produces it, and everything you can about that person or institution.
