Bought a iPad from a guy and it still has password on it and no way to contact him

I’m sorry to say you bought a brick. Without the Apple ID and password used to set up the device originally it cannot be used by you. All you can do now is responsibly recycle it.

Then the iPad is completely useless to you. Unless you can reach the person who put the lock on the iPad, there is NO WAY for you to erase, bypass or use the iPad. Apple will NOT help you. We CANNOT help you.

Read this link about buying used devices --> The All Too Common SAD Reality of Buying … - Apple Community

The bottom line is you've likely been scammed are out the money you paid and the device will never be able to used and should be recycled if you can't get your money back.

NEVER buy a used iOS based device you can't see in person and validate is fully ready for a new user.

Sorry, not what you wanted to hear.