Usually you are given a list of topics for written work in the course syllabus.
Sometimes (as in the case of the social theory course) you are offered to choose your own topic. And in the paperhelp reviews, for example, in any academic review they write all the texts in connection with the topic of the review thesis.

I advise you to pay attention to the fact that sociology is, in fact, everywhere. In a couple of years you will probably notice that the plots of most movies and TV series are too predictable for you - this is a sign that you are on the right path to mastering sociological knowledge! Also, your friends will start hating you for spoilers during the show, that's an indicator too :)

I believe that as long as there is an opportunity to "prove yourself", then go ahead and take the most unexpected cases! It can be plots from TV shows, cartoons, movies, comics, video games - anything that has some kind of story. Some of your predecessors chose not to sweat it, and wrote about the well-trodden theme of Mowgli the boy, or took stories from the school literature program. And - guess what - it wasn't just boring, it was weak writing that got graded accordingly. Take note. Life stories are just as fascinating as the fruits of popular culture. The main thing is to present them correctly to the examiners.