As people have already mentioned, quantum mechanics isn't needed for understanding wave interference, but as you've asked: The Feynman Lectures on Physics can

As people have already mentioned, quantum mechanics isn't needed for understanding wave interference, but as you've asked: The Feynman Lectures on Physics can be found online here, you probably want to read part Ⅲ. http://www.feynmanlectures.caltech.edu/ http://www.feynmanlectures.caltech.edu/