I am working in a second hand store. Last week someone (name unknown) gave me a Samsung Galaxy J5 for reselling. After doing a hard reset i started with the language, wifi network and so on, till i got a screen with : " Verifying your account with your Google account. The device was reset. To continue, sign in with a Google account that was previously synced on this device. "
I'd contact the "name unknown" for the information.
If you have proof of ownership, you could visit a Samsung Service Centre to get it Flashed (Not the same as Flashing with Odin), the device is likely protected from Factory Reset, with Factory Reset Protection.
So without the proper verification, you are likely out of luck.
There's some "methods" available on how to bypass FRP, but it's potentially sketchy / questionable / illegal?
Search on Google if you want to..
Hopefully you didn't pay very much (anything) for the device.
