Welcome to Android Central! You could connect the phone to your computer via USB and use Windows Explorer (on a PC) or Android File Transfer (on a Mac) to copy the music files from the computer to the phone. Be aware, though, that AAC files don't always work that well on Android devices--specifically, the metadata (artist info, etc.) can be messed up.
I would suggest uploading your iTunes library to your personal Google Play Music library in the cloud. Then you can stream or download your music to any device where you're logged in with your Google account. https://support.google.com/googleplay/answer/1075570?hl=en