It is important to reference all images and information you use for your school work or anything you create. By doing this you are giving credit to the person's work and/or creativity that you have used. Don't know the user name and/or password of the reference generator? Come to the library.
Creative Commons licenses, as opposed to regular copyright, allow you to reuse works created by others without asking permission from the creator. There are different types of CC licenses so make sure you understand what the license allows you to do.
The Creative Commons website is a great place to start searching for content, especially music and images.