Are they legitimate? Wikipedia and blogs are not very reliable. They tend to be short, superficial, and in some places can be just click bait advertisements.
Perform a search with the library’s search engines. Type in the novel or author and some of your keyterms/ideas, and you should be rewarded with copious amounts of sources. EBSCO Host, among others, is a legitimate academic source.
If you want to develop an idea, consider typing in the term or a phrase and see what types of responses you get. “Misogyny in Medea
Citing sources. They must be in MLA format. This website, OWL, the Online Writing Lab at Purdue University is a useful place to help you work through citation