How do I know what citation style to use?

When in university, your professor will normally assign the citation style you should use based on the subject you are studying. For example, many Psychology courses will use APA, English will often use MLA, History will normally use Chicago, and CSE is common in the sciences.

That being said, this is not always the case. It is best to check your syllabus or assignment instructions. If you cannot find the style there, then ask your professor!