Tap on Settings > Wi-Fi and verify that the WiFi is ON or OFF. Tap on the ON/OFF icon to turn WiFi ON.
All available WiFi networks will appears under “Choose a Network”, networks with (padlock) icon shows that this is security enabled network and (Signals) icon shows the strength of WiFi networks singles.
Tap on the WiFi network that you want to use. If WiFi network is security enabled then you have to provide security key for it, after entering the correct key for security enabled WiFi networks you will be able to connect your iPad to wireless networks.