There is a series on youtube by VoidRealms that walks you through using the basics of C++ Qt/QWidgets that I found helpful when I was learning Qt.

https://www.youtube.com/watch?v=6KtOzh0StTc&list=PL2D1942A46...

I was trying to learn Qt, and it just wasn't clicking, but watching these videos and suddenly Qt just made sense. This was nearly 10 years ago, and note that some of the syntax has changed, particularly Signals/Slots.