Which platform and language to choose for an Android application?

Question

Android

I am a web developer (HTML+CSS+JS+PHP). I am not a pro, but I have basic knowledge in these areas. He was mainly engaged in the backend of state sites (personal accounts, interaction with SMEV). And I had an idea for an Android app. This application is native, it does not send or receive anything to the Internet, but it must store certain data (in a local database or in a file, there are not many of them). The OS of the computer on which the application will be developed is not particularly important (an active user of both Windows and Linux).
The question is. What platform and PL to choose for the application (specifically in my case, taking into account the available knowledge and tasks)? How to store app data on android device? Where there is high-quality documentation for developers.

Answer 1

I make mobile applications on 1C. But this option is unlikely to suit you.