Hi there and welcome to Just Answer, my name is ***** ***** I look forward to helping you.
I’m sorry to hear you're having trouble. I know that can be frustrating. Hopefully, we can get this resolved quickly.
You will then need to reset the device, it will remove all data from it but this we cannot avoid sorry.
To do the reset
Connect the iPad to the computer and open itunes (install it from www.itunes.com if you do not have it)
Hold the power and home button down on the unit until you see in iTunes
"iTunes has detected a device in recovery mode"
Click Restore, let this complete and it should now work.
Note the restore can take up to a few hours depending on your internet speed, it will tell you when it is done or give an error if there is an issue.
Let me know the results please