my ipad mini says "iPad is disabled connect to iTunes" what sould i do

Connect it to iTunes on your computer.

Forgotten Passcode or device disabled after entering wrong passcode

See the second part of the article:

Use Find My iPhone

If you enabled Find My iPhone, you can use it to erase your device.

1. Go to icloud.com/#find to see if you enabled Find My iPhone.
2. Click All Devices at the top of your browser window.
3. Select your device and click "Erase [device]" to erase your device and its passcode.
4. Use the Setup Assistant on your device to restore the most recent backup of your device.

Use recovery mode

Follow these steps if you never synced your device with iTunes, if you don't have Find My iPhone set up, or if you can't get to your own computer. You'll need to put your device in recovery mode to erase the device and its passcode. Then you'll restore your device.

1. Disconnect all cables from your device.
2. Turn off your device.
3. Press and hold the Home button. While holding the Home button, connect your device to iTunes. If your device doesn't turn on automatically, turn it on.
4. Continue holding the Home button until you see the Connect to iTunes screen.
5. iTunes will alert you that it has detected a device in recovery mode. Click OK, then restore the device.

The only way to reset the passcode is to restore.

Hopefully your cousin has a recent backup.

You're welcome