A laptop serial number doesn't show up on the Internet. You can't track a stolen laptop through the serial number.
Your IP address you used on the Internet isn't won't help you locate a stolen laptop. It will have a different IP address if it connects to the internet with a new ISP account.
File a report with the police in case it's found.
Notify the laptop manufacturer in case the laptop ever needs to be serviced.
The Laptops NIC MAC address isn't visible over the internet.
If you were a LAN admin (like on your home network) you'd be able to see the MAC address on your own local network. But on the internet you'd only be able to see the MAC address of the modem/router - not the individual devices behind the modem/router.