So I had my old iPhone synced with iTunes and i just got a new iPhone but now when i plug in my new iPhone my old iPhone still pops up under devices. how do i get rid of the old iPhone under devices?
You may have enabled Wi-Fi syncing for your previous iPhone. Connect the previous iPhone via USB and under Summary, uncheck the option for "Sync with this iPhone over Wi-Fi. Click Apply and once you Eject the iPhone, it shouldn't appear unless it is connected by USB.