A:AnswerNo, as Galaxy S7 only have a mirco usb port, no mini HDMI port.
What you need is https://www.bestbuy.com/site/reviews/samsung-micro-usb-to-hdmi-adapter-white/2003027
A:Answeryes, but you should look into a google chromecast or a firestick if you just want to mirror your screen sans the cords. Otherwise, yes it will work.