APA Format Paper

Hello,
I'm writing an APA format research paper on the topic of gun control. This is one of the first such papers I have written (this is my first semester in college). The instructor's instructions were rather vague and he just stated he wanted the paper in APA format. I am including several different subtopics in the paper, each with several paragraphs in it. What is the proper format to differentiate one subtopic from another? Do I include a heading at the beginning of each new subtopic?
Here is basically how my paper outline looks:
Main Topic: Gun control in the U.S.
Subtopic1: Evolution of Modern-Day Gun Control
Subtopic2: Flawed Studies on Gun Control Effectiveness Subtopic3: Failures of the Assault Weapons Ban
Subtopic4: Benefits of Concealed Carry
Subtopic5: Cato Institute Study
Each of these subtopics will have several paragraphs. It isn't practical to include everything on one subtopic under a single paragraph. I tend to think it would be difficult to follow if I just had all the paragraphs together like an essay. Anyone familiar with APA format who could help?
Thanks.