How do we move on from a website to an App?

So me an a few friends recently launched our first website. A website were you can play simple games like pong or tetris. The higher the score, the more coins you get. But the website is pretty much done and we wanted to make an app. Since we don't really know much about android studio we need some help. Is there a way to convert the website to an app? So that we take our login and registration forms and just put it in the app or do we have to code everything from the beginning. As a database we use MySQL.