I usually use the latest available Python version at any given moment.

The reasoning behind this article and the programming style that I describe were a result of my own experience. I believe that most Python resources teach you the basics to get started ASAP, but few of them actually cover good programming practices, so I can't really give directions in this sense.

I can however suggest to take a look at PySimpleGUI. It's a library that reimagines UI development in a more streamlined fashion and my new favorite tool to create desktop applications. For the most part it's just a wrapper around Tkinter but it improves a lot on it: for example the event handling queue that I built for myself in this tutorial is the default way of doing things. Thoroughly recommend it.