Should i turn on Find my phone in my iphone?

It asks to turn on location service. Is this okay to do that?

Absolutely, its a great feature, once its on only you can turn it off (so if its stolen you can locate it), and you can remotely wipe it, or make it beep in case you lose it in your house. You can view it at http://www.icloud.com/...icloud.com

Well yea. That is in case the phone is lost or stolen you could use that app to find it.