Application for android, where to start?

Question

Android

My level of knowledge:
I write simple programs on arduino, I made a couple of sites on html, css.
I don't know anything about Android apps.

What I need:
1. An application for android, which will contain information in the form of a list that can be added, deleted.
2. On the devices of which the application is installed, the information is synchronized and updated.
3. Perhaps a site from which it will also be possible to upload information to the application.

The app will be used by 5 people at most.

In fsh visually sketched what I want:

spoiler

As far as I understand, we need a database where everything will be tied up, but I have no idea what and how.
How can this be implemented?
With what tools?
Where to read? What to learn?)

Answer 1

list RecyclerView
db firebase