why cant my ipad connect to wifi? it says it cannot connect to server

Hello,

Try resetting iPad's network settings in Settings > General > Reset > Reset Network Settings. Be certain you do not select Erase All Content and Settings as this will erase all of your information. It is a good idea to perform a backup of your iPad prior to resetting its settings.

If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network - Apple Support