Creating a navigator on Android. How?

Question

satellite navigation

There is a desire to create an application - a navigator for mobile devices (for a start, only Android), to simplify the interaction of ordinary people with the public transport system of a small city.
The minimum functionality that I wanted to implement:

• where is the user
  
• what stops are nearby
  
• what taxis pass through these stops
  
• when you can leave (based on the timetable)
  

Data that is known and can be used in the application : a list of all routes, with numbers, routes and schedules for weekdays and weekends.
I have never been involved in programming for Android, so I would like to know briefly how difficult it will be to create such an application, what languages, libraries and APIs, at a minimum, may be required for this.

Answer 1

It's not hard to write this. The problem is rather to keep the schedule up to date.
For example, you can set the following:
Language - Java
Maps - google-maps
For a database - FireBase