The answers about getting started with Kotlin and Compose are good, but I'd like to offer for your consideration that your app may actually be more appropriate to build as a website. Food for thought.
F-Droid
F-Droid is an installable catalogue of FOSS (Free and Open Source Software) applications for the Android platform. The client makes it easy to browse, install, and keep track of updates on your device.
Matrix space | forum | IRC
https://developer.android.com/codelabs/basic-android-kotlin-compose-first-app
and if you've never written a line of code in your life:
Android Studio is the primary toolkit for developing native android apps. If you have no background in programming, there are some more visual tools like Budibase (open source) or Softr (closed source), but you are likely to run into difficulty getting them to apply logic the way you'd like.
If you're a tinkerer, then honestly I'd look into learning more about Android Studio and Kotlin, the language most used these days for app development on Android.
Android Studio is proprietary
Imo that's fine. It's also still the best tool for learning since it's the most widely supported one, and contains the greatest amount of documentation for working with android development. It costs nothing to use, and doesn't lock you into any kind of ecosystem you can't later migrate from.