If you installed WAMP without changing anything then your default port would be 80. So if you want to change your listening port simply follow this instructions.

1. Left click on the WAMP icon on your system tray.
2. Go to Apache then click on the httpd.conf option.
3. Press Ctrl+H to open the replace function of notepad.
4. Enter 80 on the Find What field.
5. Enter your desired port on the Replace with field.
6. Click on the replace all to replace everything.
7. Save your httpd.conf.
8. Right click on your WAMP icon on the system tray then exit.
9. Run WAMP again and now your port is 8080. You can access your localhost by using this address on your browser http://localhost:8080