Will i loose all my data in this iphone sync?

So i got the iphone 5s for christmas and its my first time plugging it into my computer, my options are backing it up as a phone last backed up from 2012 or set up as new iphone will setting up as a new phone erase all my current data?!

It will not erase anything. It's just going to create a new profile for your new phone in iTunes. It won't change anything! I know it's scary, but you're safe to set it up as new. Again, it's just an iTunes profile for that phone. (That's how it can tell it is a new phone and not restore the old backup)