APA is more commonly used to cite sources within the social sciences. Some curricula require the use of a specific format, so always be sure to check with your teacher or professor to make certain that you are quoting your information properly. APA style is quite a bit different from MLA, so if you're not used to it, you will need to use a style guide to format your citations. Style guides are easily available online.
When using APA style, it is permissible to write (or speak) in first person--using "I" and "We" in active voice. A good rule of thumb is that when using APA, you are presenting the material based upon you being the expert, and that this is your personal research. Adherence to appropriate APA style lends credibility to your work.
Have you ever read something and wondered whether you should underline a book title, or italicize a movie title? Often the differences are slight (such as a particular piece of punctuation in a certain place), but they provide a common format for people to search for information. A very general format lists the author first, by last name, then the date of the publication in parenthesis, followed by the publication title and page numbers used. Volume numbers for journals are often italicized.
In a speech class, or any other class where you are required to give a public speech, you can be instructed to use APA in two different ways. The first is if you are quoting another source for your own debate or speech. Follow the specific directions in your style guide (they can change by year) for each type of material--whether it's a speech, an online journal, a book, or a YouTube video. Each type will have its own format. The other way that APA can be used in the classroom is when you speak. It could be that your teacher or professor wishes you to use a less formalized style of speaking. Be sure to check with them before writing or performing your speech.