My iphone won't connect to itunes? - 3

I downloaded the new iTunes and last night I plugged in my brothers Ipad so I could download a song for him. Now I want to download a song but it says my device malfunctioned and can't be found.also, I downloaded the songs I want to put on off of youtube so they are not on icloud, plus, I would like to backup my own phone to my own computer…

Have you set the correct time? I know sometimes itunes can be picky when an I device is the wrong time.

Did you restart your computer after the update?