my ipad mini wifi toggle switch isnt working

First, make sure that you don't have restrictions set for the iPhone by going to Settings > Screen Time > Content & Privacy Restrictions > Content Restrictions. If Content Restrictions is turned on, then there may be a setting enabled that is preventing Wi-Fi from being changed. Temporarily toggle off Content Restrictions to see if you're able to turn on Wi-Fi again. Learn more about Screen Time restrictions here: Use Screen Time to get insights about how you use your device. 

Then Reset your Network Settings. Tap Settings > General > Reset > Reset Network Settings. This also resets Wi-Fi networks and passwords, cellular settings, and VPN and APN settings that you’ve used before.

Try a hard reset of your iPad by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons.

Good Luck!