Can't update my iphone 4 apn settings?

I have an unlocked iphone 4, and I have my cellular data on but I don't have to options to update my apn settings or whatever it's called, I went to settings>general>network>turned on my cellular data
but i don't see my options to update it, how can i fix it.

So you update to the iOS 6 update? Because many people are reporting problems with Wi-Fi and connections and such since they updated. I've been having problems with my phone freezing too:/
hoping they come out with an update to fix the update soon lol