If its jail broken then you can get it from Cydia, i think in Cydia you can even get a converter for it and it allows you to set custom ringtones, however if you have just bought it, and it was brand new i don't think it is jail broken in which case you need to Download ringtones from App Store. I'm not sure how you set them as ringtones though as i only have an ipod which i jail broke my self. Firmware version 4.1 (i think)