How to Use Wi-Fi on an iPhone Without a Data Plan
The iPhone is a cellphone made by Apple that can connect to the Internet over Wi-Fi or a cellular data network. If you don't want to use the cellular data network, perhaps because you are trying to save money on your data plan, you can disable network access and just use Wi-Fi. The iPhone has a multi-touch screen that you tap and touch to activate settings and run applications, such as the included Safari Web browser, Mail and YouTube apps.
Press the "Home" button at the bottom of the iPhone to return to the home screen.
Tap the "Settings" icon on the iPhone's home screen.
Tap the "Airplane Mode" option to "Off" if it is enabled. When Airplane Mode is enabled, you will see an icon of an airplane in the iPhone's menu bar, and you won't be able to connect to the Internet over Wi-Fi.
Tap the "Wi-Fi" option to "On."
Tap the "Cellular Data" option to "Off" to disable using your cellphone provider's data plan. Now you will only connect to the Internet over Wi-Fi.
Tap "Wi-Fi" to access the Wi-Fi settings. Tap the "Ask to Join Networks" option to "On" if you want the iPhone to automatically look for Wi-Fi networks whenever you are in range of a previously used Wi-Fi network. If you are already in range of a Wi-Fi network that you've previously connected to, the iPhone will remember it and automatically connect to it. Type the password at the prompt if you are connecting to a Wi-Fi network that requires you to log in.
Press the "Home" button to return to the home screen.