How do I learn programming & subsequently software development (Android & iOS in particular)?

Start with reading the right articles. Do not fall into click bait and fancy headlines of videos/tutorials/articles.
Another important thing that mostly goes ignored is that programming be it android or iOS/Swift requires you to learn how to implement logic, provide structure to support your need (Design and Create) which everyone talks of & also it somehow passively also wants you to learn the tools/IDE/software seamlessly so you can focus on doing and coding rather than struggling to set environment variables, checking installed software and directories.
Understand we always prepare ourselves to learn the hard part by watching other successful people or reading or sometimes intuitively the boost to write code again surfaces, what initially stops you and gets you tired is the switch on and offs & set create or prepare the setup to go and actually sit and code.
Two hours into your selected course of choice or maybe just following article step by step you realise this is just where i was able to press button and run the tools actual coding beings now. That is at times tiring for beginner & expert alike.
Everyone wants to type there first Hello World program (basically choose your weapon of choice and learn the respective syntax print that on some fancy colored text editor or on actual cockpit styled IDE) & you have it some corner of screen would say Hello World.
That's your first actual app in progress but reaching this level would require you to do bunch of things first & that is tiring.
So divide your learning into a threshold & liftoff sequences. You wont find this perception in any book it is coming from personal but valid failure and initial struggle. Every course will skip or be quick with this initial part of threshold, find a course or program or educator who helps you get on board easy and well first.
Because everybody can teach you what book says beyond that all programming concepts are same in beginning once you know that you can then specialize into android specific aspects.
All that i wrote above applies specifically to but also not limited to android programming in java / kotlin / flutter
Have fun & begin correctly (I could have said start right but then its not correct way that's the tiny difference. You wouldn't know its more aesthetic until you get the better more fitted way)