How do I play Mirage?

I wanna main Mirage but I'm not sure exactly how to use him. I'm pretty new to the game so my knowledge about everything is limited. What's a good public build to use and what's the idea of the character? From my experience I need to hit headshots. If I hit headshots then I do insane damage but if I don't then my damage is terrible. Advice for what to do at different points and how to lane would be helpful too. Thanks.