Social media will bring you suggestions for research into popular culture, but which topics have enough material about them to sustain a college paper? One way to find out is to see how extensively the topic is covered in the news.
Go to Marymount Manhattan College's Nexis Uni database. Nexis Uni aggregates (library-speak for "gathers") English-language newspapers from around the world into one place, and makes them accessible via a keyword search. Even if your professor wants you to use "scholarly" sources, a newspaper search will tell you how many newspapers cover your topic, your topic's geographic spread, and how long it has been in the news.
For example, you've heard of the Black Dahlia murder, the subject of "true crime" treatment in several genres, but you know it happened long ago. Is there any contemporary interest? Go to http://www.mmm.edu > Quick Links > Library > Databases and type in Nexis Uni in the search box on the right, then click on the link that comes up on the lower left. Go to the upper left, click on all Nexis Uni, then click on the box next to News in the middle of the left, to limit your search to news sources. Where you see Enter Terms enter "Black Dahlia," with the quotes around it, so the search engine reads it as a phrase. When this was tested, the first result was a January 15, 2020, article entitled "Stonington Players read new play about posthumous efforts to solve Black Dahlia slaying." So it's still in the news. The column on the left indicates that there was a spike in interest in the case about 2007 (when a movie came out), that interest seems to be concentrated in newspaper (rather than other forms of media), but that it is geographically widespread. There might indeed be something in the scholarly literature on the case.
Nexis Uni's focus is born-digital data. For data from the pre-digital age, use the database ProQuest to consult back issues of the New York Times. Select Advanced Search; the Times has come out almost every day since 1851, so there's lots of material. Use the most precise keywords you can; it helps to put one keyword in each box so you can swap them as needed. Also, use the Boolean feature; you can change each "and" box to "or" to get synonyms (Siam OR Thailand) or exclude something (using "not" ad will screen out advertising for a book, leaving reviews and author profiles). Also, take advantage of the date filter.
For example, you're studying the pop culture character King Kong and you want the review of the original movie. You check imbd to get the date of the movie: April 7, 1933. Go to ProQuest, choose Advanced Search, enter "King Kong" in the first search box, change the AND between the first and second search boxes to NOT, and add the keyword ad. Given that reviews can precede releases, set the dates for January 1933 to June 1933--plenty of time for reviews and even letters to the editor. Touch Search and up comes a list of finds. About midway down, on March 3, 1933, is an article titled "A Fantastic Film in Which a Monstrous Ape Uses Automobiles for Missiles and Climbs a Skyscraper." There's the review.