Proper way is to build it from scratch. Create a XML or Json based API for the Website which can be accessible from the Android App. Learn how to call REST APIs and how to parse XML/JSON.
I got this great idea from Website Builder "Weblium"
Regards
A lot of people create applications, though they have websites. And I'm no exception. In my opinion, the best choice is one of website builder apps for Android like Wix, Weebly or Jimbo. It is possible to check a review of the most popular of them on https://www.webbuildersguide.com/website-builder-articles/best-website-builder-apps-for-android/. It can provide you with pros and cons of every web builder.