Welcome to MobiFAQ! The easiest way is to connect the phone to your laptop via USB cable and use Windows Explorer to drag and drop the files. Copy the files to the phone's Music directory (or create your own).
If you want to transfer them wirelessly, then you need to be on the same wi-fi network (presumably your home network). A WPS PIN is needed only if you're connecting either device to your wi-fi network via WPS protocol. If both devices are on the same wi-fi network, you can use an app like AirDroid
to transfer files.