How to choose a study methodology?

Question

Android

Hello, my name is Denis and I am [s]stupid[/s] unable to learn Android Dev.
With Java, everything was more or less clear, but I studied it in order to transfer to Android.
In general, everything was fine, it seems that some kind of progress has begun, but at the stage of creating other Activities and onClick methods, that's it. End. I mean at all. There is no other material and that's it. Specifically, one book seems incomprehensible due to the abundance of terms for experienced programmers and developers, the other describes the theory too much without issuing information "where it all sticks", and therefore - simply flies out of my head when it comes to practice. Other courses, incl. video - either they run too fast, or they chew too much. And all this turned out to be so critical that something was a little wrong - it was as if a toggle switch worked in my head and "the pot refuses to cook." In particular, I got stuck at this moment in the official tutorial:
res/values/themes.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <!-- the theme applied to the application or activity -->
    <style name="CustomActionBarTheme"
           parent="@android:style/Theme.Holo.Light.DarkActionBar">
        <item name="android:actionBarStyle">@style/MyActionBar</item>
    </style>

    <!-- ActionBar styles -->
    <style name="MyActionBar"
           parent="@android:style/Widget.Holo.Light.ActionBar.Solid.Inverse">
        <item name="android:background">@drawable/actionbar_background</item>
    </style>
</resources>

For a simple reason - nowhere is it indicated how and where to get this themes.xml, and when I try to directly create it and write the code adapted to my application, it simply refuses to work. Google? Yes, but apparently not enough.
And every time after probably the hundredth attempt to start that book, or this course, breakdowns and real tantrums begin.
If the question is still not deleted:
1. What should I do in such situations? I don’t want to look for a simpler way, I need to overcome it, but I have no idea how.
2. Is there a full-fledged source of knowledge on android that you can just read, do, and understand at the same time?
3. Is there some way to learn through practice, without going through topics sequentially?
Thanks in advance to those who responded, as well as to the moderator, if the topic lasts at least a day.

Answer 1

Android dev is an adventure.
And to understand something in it.
Create a small application.
Along the way, figure out what and how.
More practice, code more often.
Create your next app.
So soon your happiness will come.
And just like that, and just like that...