Importing cd music to itunes

Of course, iTunes does not exist on an iPhone. (You posted your question in the iPhone community.) Nor does iTunes exist on Macs any longer. So presumably you’re asking how to do this on a PC.

Import songs from CDs into iTunes on PC - Apple Support

If you have Windows→Import songs from CDs into iTunes on PC - Apple Support

If you have a Mac→Import songs from CDs into Music on Mac - Apple Support