Thanks for using Apple Support Communities.
For more information on this, take a look at:
iOS: Troubleshooting Wi-Fi networks and connections
- Verify that you're attempting to connect to your desired Wi-Fi network.
- Make sure you're entering your Wi-Fi password correctly. Passwords may be case sensitive and may contain numbers or special characters.
- Reset network settings by tapping Settings > General > Reset > Reset Network Settings. Note: This will reset all network settings including:
- previously connected Wi-Fi networks and passwords
- recently used Bluetooth accessories
- VPN and APN settings
iOS and OS X: Recommended settings for Wi-Fi routers and access points
Best of luck,