Scholarly and academic are interchangeable words when used to describe the type of information you are expected to consult in college.
Peer-reviewed or refereed is a subset of academic information, in that it is an even more stringent quality control on your source, and it only applies to articles.
Indeed you can get academic and peer-reviewed articles from Google Scholar and other open websites, but the best strategy is to use databases provided by the library. Other information you find online (news, personal websites, social media) are not scholarly, but can be useful for different ends.
SCU subscribes to hundreds of databases that provide access to proprietary information in every discipline represented in the degrees awarded at our school.
For this class, you will want to use databases that are specific to history.
Once you exhaust the history options, you can also try multidisciplinary databases, but you will have to use more or different keywords since you are not solely searching a body of historical research.
While many of these articles will contain reproductions or large quotes from primary sources, they are considered secondary sources.
To get a list of all the databases available at SCU, go to the library home page and click on the DATABASES tab.