Okay, so there are different kinds of ports. For the Pi in the local network, the LMS usually uses port 9000.
However, open ports, for example for VPNs and the like, are a danger for the LMS. If you have not worked with anything to route a connection outside your local network, you do not need to concern yourself with this.
It might be, your installation was just somehow faulty. You can try installing anew and keeping the installation running uninterrupted for at least 15 minutes. Try selecting the version 7.9.1.