Questions about Multiplayer and Networking?

First I apologize if you find this question too subjective I just could not seem to find what I was looking for by myself.

I am making my first multiplayer game in unity and have absolutely no idea where to start with multiplayer and networking the script API confuses me,and the tutorials are lacking.So I was hoping someone who knows this area much better than I do would give me some advice.

I don't like the NetworkGUI system as firstly is uses old GUI methods instead of unity's new UI system, and doesn't teach about much that is actually happening inside the code I want to know what code i need to use. What I want is my game to have the ability for players to Host servers themselves and Join servers that someone hosted, without having to know their IP address, preferably a server list could be created. If someone could point me to code in which I would go about doing something like this that would be enough. I am 100% unfamiliar with how IP addresses, or ports work.

Once again i'm very sorry if this question has been asked many times, or is to subjective, I just could not spend my whole day checking every single related answer question on this site... there is a lot.