You're going to need to scan your area for all of the Wi-Fi networks that your Mac can reach by starting the Wireless Diagnostics Application.
This will show you all the other Wi-Fi networks your Mac can see, what frequency band and channel you are using.
To perform a WiFi scan on your Mac OS
1. Hold the option key on your keyboard and click on the Wi-Fi network icon in your Title Bar.
2. Click Open Wireless Diagnostics. A "Wireless Diagnostics" window will open. Ignore it for now.
3. Click on Window in the Title Bar and select Utilities.
4. Click Scan from the drop-down menu. You'll see a list of all of the Wireless Access Points in your area.
5. You can click Scan Now.