First of all, you should make sure that the QT you are talking about is a programming framework, not a language chat tool.

The biggest point of Qt is that it is cross-platform and supports many mainstream operating systems, but I personally feel that it is more promising to do it under Linux, especially to do some UI programs and background logic control on embedded Linux. It is pure C++ grammar, so you should be proficient in C++. At present, QML is a good UI, and a few simple words can make a cool effect. Key words: Linux, c++, embedded, research.