@muhammadsa29369 not sure why you would want to install iTunes on your phone. You do not need it to play music. For that you use the innate App "Music". Where you do need iTunes, is on your computer. You use that to sync your iPhone with your computer, not the other way around. Remember, your iPhone cannot be upgraded with anything above iOS version 7.1.2
Do not get confused with the iTunes Store App, which uses a purple box with 5-pointed white start in it, as icon. That is not the iTunes you need to sync your music/files :-)