Do iPhones have Wi-Fi everywhere with a no data contract?

I'm getting a iPhone 4 on contract, the contract I'm getting has unlimited text, 500 minutes but does not have data. (0gb)
Will this mean I won't be able to assess the Internet when I'm out?
And if I do choose this contract will it mean that I won't be able to access facebook/snapchat when out?

It means that you can't go on the net without a Wi-Fi hub somewhere. So yes, if you are out at a park and want to go on Fb or Snapchat, you won't be able to.

What this means is you have not purchased any data to use through the 3G connection on the phone. If you are in a Wi-Fi hotspot though you can use that still. A lot of people have it set to automatically connect to the Wi-Fi signal over the data signal just to save them data amounts so they don't go over. Also just so you know make sure you know your 3G is turned off in your settings, just because you have 0gb doesn't mean the phone can't still connect to the data and use the data. So always make sure the 3G is off and the Wi-Fi is the signal being used!

No phone has Wi-Fi everywhere. Wi-Fi availability is due to the availability of router/modems & their range in your area.

Well if you do have no data, which is odd since most smartphone plans have that as mandatory, then no Wi-Fi, no internet. Simple as that.

I think you should reconsider and get a contract with at least a small data allowance