You won't have the possibility to bypass that enforcing restriction. Firstly, contact the owner of the phone and ask him to provide the email address and password set as temporary just so you can get access and remove the FRP lock. If he refuses, open a case on the website that you bought the phone from. If it's eBay, they will offer a full refund and the owner's account disabled.
If that's not possible, visit a local phone service shop and they will wipe the phone clean by removing any lock it might have.