I Updated my iPad to 13.5.1. Now I can’t Access the internet using our WiFi

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

Have you tried a simple 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!