New iPhone 6 set up help. How do I sync with out restarting?

Just a day ago I got the iPhone 6. I turned it on went through all the setting up and stuff, i started it as new because my old phone had little worth keeping, I could get it all back in minutes. So after the basic set up, I downloaded the few apps i had, sent some pictures over and signed up my emails and stuff. Now that's its all set up I plugged it into my computer to get my music on it, the only thing I had left to do. When i plugged it in, in iTunes it's asking if i want to set up my phone as new or from a backup. I don't wish to do either, I already set it up. If i click start as new will it erase everything I did to it today and yesterday? I wish to keep it exactly how it is now but then add my songs to it.

Suck my but

Set up as New phone will not touch anything on your phone,
Back up will replace your current state with an old back up you had, which will erase everything on your phone.
https://www.youtube.com/...cv-nPSEqLw
some videos to help set up and manage your phone.