A topic is a general inquiry you are interested in answering. It is not a statement, but a question.
Examples: Are same-sex parents as effective at raising children as heterosexual parents? How does the incarceration of a parent affect a child's concept of family? How has the concept of childhood changed, and what is its impact on current day society?
Steps to formulate a topic:
Read your assignment and note any requirements.
Is there a required page length?
How many sources do you need?
Does the paper have to be in a specific format like APA?
Are there any listed goals for the topic, such as synthesizing different opinions, or applying a theory to a real-life example?
Formulate a general idea.
Look at your syllabus or course schedule for broad topic ideas.
Think about reading assignments or class lectures that you found interesting.
Talk with your professor or a librarian.
Check out social media and see what has been trending that is related to your course.
Read and watch the news to see if there is anything going on related to your course.
Do some background research on your general idea.
Read an encyclopedia entry.
See what your course notes and textbook say about the subject.