Failing to open manager server trial version on WiFi so that we can test if other users can access it
This is not a Manager issue, but a local networking issue. If you do not have the skills to operate your network, you should consider the cloud edition. You can also try it for free.
I have to second what @tut has said, the server instructions (linux version—since you didn’t specify) are pretty clear, so if you have entered the correct IP address of your server, with the correct protocol and port number, it will appear on the screen.
generally: http://127.0.0.1:8080 (but use your server IP)