Hi there!
My name is Fernando, nice to meet you.
If you have Google services you can trace (or should) the phone with the app Find my phone.
Also, if you too have a registered on Samsung account you can also trace de phone in your personal account that are linked to your phone.
I think that this is the fastest one and more easy way to do it.
The next step is go to you service provider and check with tem how they can trace the last time that the phone was connected to they service (last know antenna = last know location)
Hope that this info can help you out!
Cheers,
Fernando