How do I create a Peer-to-peer game?

I am trying to find a good tutorial on where it explains how to create Peer-to-peer game by coding in C# also on where it shows a player connects to another player in their Unity game. I know a bit of stuff on how the Internet works and how data is transmitted through it, but is there a beginner friendly guide? I did code a game on Unity for myself but never created a two player game.

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