please help

Need more info. Where is it locked? What are you trying to do that is requiring your iCloud password?

GB

You wouldn't know if it was stolen or not. The device is locked by the Activation Lock which requires the previous owner to remove the device from Find My iPhone:

Removing Previous Owner from Device

If the seller cannot or will not follow the steps above, return it for a refund as it will be unusable for you. If the seller is not cooperating, contact eBay - they have a guaranteed return policy.

Sorry,

GB