Audacity is a free, easy-to-use, multi-track audio editor and recorder. It works on Windows, Mac, Linux, and more. If you'd like to put it on your own computer, you can download Audacity. Many library computers also have audio recording and processing software installed.
The tutorials may be a particularly good place to start, especially the Mixing a Narration with Background Music.
Equipment
Although smartphones and computers are capable of recording audio, we highly recommend you use an external microphone. There is one available for check-out at the Circulation Desk. If you do use a smartphone, using a tripod with it is highly recommended. Those are also available for check-out.