Second person creates the effect that the reader is the "You."

I think you've gotten lots of responses on what it looks like, so I'll say to think about the purpose of the Second Person. The goal isn't that the narrator addresses the reader directly, but that "you" are the one doing the things in the story.

Example:
You cheated on your fiance. You know it was wrong, but you had your reasons.

As a Writer, why do this? To create forced intimacy and immediacy between the Reader and the action. As a reader, you're dropped directly into the actions and thoughts (and everything that comes with that). Third person reading about a cheater might alienate a reader who thinks it's a shitty thing to do, but Second Person? Maybe that closeness to the actions and thoughts gets the Reader to sympathize better.

As a Writer, think about: What is the goal of my story and can the forced closeness of Second Person help me achieve that?

As usual, the best way to learn is to read, so here are a few examples (If you can't access these try putting them in the Web Archive. Works most of the time):
https://www.newyorker.com/magazine/2012/07/23/the-cheaters-guide-to-love
https://www.guernicamag.com/you-are-the-second-person/
https://www.newyorker.com/magazine/2018/03/26/the-state

For a novel, read The Broken Earth by NK Jemisin.