1. Open a web browser (google Chrome) and type in: chrome://system into the address bar and then press enter. 2. Find where it says: ifconfig and click on expand. 3. From the wlan0 section, view the link encap:Ethernet HWAddr (MAC address). 4. This is where you MAC address is. It is the numbers at the end of this line.
See http://support.verizonwireless.com/clc/devices/knowledge_base.html?id=38506 if you need a better walkthrough.
You have to connect to your router using an Ethernet cable. MAC address filtering is for wireless connections only. After you connected via a cable, you can log in to your router and correct the settings.