I have an iPhone 5s and want to set a ringtone of my own audio?

On iphone 5s if you have a free music downloading app how do you make a audio on it as a ring tone

You have to plug your iPhone into a computer and load up iTunes which can be downloaded on Apple's website. You have to take the downloaded music and put it into your iTunes library and then after the downloaded music is converted into iTunes music, you can then go into settings in your phone and choose your ringtone. Sorry I wasn't able to go full in detail but I hope this worked!