Hello...I want to build an Android app that meets these requirements:

-Delivers "push" notifications to subscribers / end users. (example: members of a golf club).
-Contains a "QR" code for new users to scan to get the app.
-deliver to Android ver 1.6 and higher on mobile smartphones.
-allows a "mockup" or prototype app to "demo" to prospect to convince them to buy app. Final App must be uploadable to the Android App market.

I am not a coder but have a technical background spanning biochemistry to robotics to report writing in SAP.

I seek a book or course to learn how to build an Android app with the features above.

A company is trying to sell me a "drag and drop" software "system" for 1000 USD that builds the app in 1 hour with the above features. I'd rather learn how to build the app with the features I need to better understand the mechanics of an Android app.

Any suggestion would be graciously received.

Thank you in advance.