Visit this Wakelet to explore copyright free/friendly images to use for school projects. Remember that you should always CITE the sources you use, and that applies to images and music too.
The links listed below will take you to websites where you can download music or sounds for free. In order to not break copyright laws, you cannot use this music in any commercially used projects or videos--in other words, you can't be making a profit off the work you have done. Also, you are not allowed to share the files. As always, click on the "About Us" link or the "FAQ's" link to find out the specific usage guidelines. Remember that you should always CITE the sources that you used, and that applies to images and music too!