First Implementations

Hey everyone,
I have an idea for a new project (it’s an app - obviously; don’t get offended now) I want the app for Android only right now. I want it to start up and allow the user to setup a fingerprint scanner (if applicable); then that’d be the end of the app. All they have to do is close it and it’ll run in the background when something specific (like network) changes and then send them a Local Push Notification like “Hey, so [it] changed!”.

I’ve thought maybe I’d implement OneSignal, Background Mode, and Android Fingerprint Auth.

I need suggestions, ideas on what’ll be the most efficient/easiest way to instantly deploy the app that way whenever the network (it’s a network management app) detects a change it’ll alert the user with a Local Push Notification and update the change under their account on the app.

Which Storage would be best for a simple local only app?

What would be the best approach in achieving this?