Prerequisite knowledge for writing KDE apps?

[HiPhish]

Hello everyone,

I am new to GUI programming, but I have been using Plasma for years and I 
would like to try my hand at writing a GUI application myself using KDE's 
technologies. However, the KDE stack is quite daunting: first you have C++, 
then Qt, then QML, then KDE Frameworks, then Kirigami, and finally somewhere on 
top of the stack my code is supposed to reside. I tried coding along with the 
KDE starter tutorial, but found that there is a lot of prerequisite knowledge 
I need first in order to make sense of the code.

My question is, what prerequisite knowledge do I need and what is the best way 
of learning it? Obviously I need to know C++ and I am decently familiar with 
the language. The next question is Qt, which I tried to get into, but the 
official resources are very divorced from KDE and the Qt company really badly 
wants you to use their entire suite of tools. I'm afraid that will send me 
down the wrong rabbit hole. Are there some "Qt the KDE way" resources 
available?

I want to do as much work as reasonably possible through code rather than GUI 
tools. I have a very well decked out Neovim setup, so that's my editor of 
choice if it matters. I prefer written resources, even books (if they are not 
outdated), but video tutorials are fine as well.