Will I need to leave my computer on 24/7?
If you plan on stream live audio, then yes. For as long as you want the server to be broadcasting, you will need to provide the audio live for it to broadcast.
However our Auto DJ doesn’t require you to connect yourself, as the Auto DJ will connect and stream on your behalf. You will simply need to upload audio in the form of MP3s in the client area and enable the Auto DJ. It will play the MP3s you’ve uploaded and you’ll be free to use your computer as you like. Please see this article: SHOUTcast vs ICEcast?
Play what you like to the world!