Primary sources can take many different forms. Letters, accounts and other kinds of documents written at the time of an event or era allow a nuanced and detailed understanding of historical issues. The histories and studies you wil be finding and reading draw on primary sources in order to better understand events, people's actions and other factors which contributed to the social issue you are exploring.
When reading a journal article, book chapter or other historical study (also known as a secondary source in contrast to primary sources), check the footnotes and bibliography for evidence of the kinds of primary sources the author consulted. You can then look for specific titles in the Tripod catalog.