Am I backward or is the TK too complicated?

Question

C++ / C#

Here is tz.
Responded to the most default vacancy for a junior
Programming in C#, knowledge of its standard library, OOP;
Experience in developing 3D games for mobile devices in Unity from scratch;
Unity knowledge and experience, the more the better;
14k - 27k hryvnia

I failed to implement the idea in an adequate way. I feel like I'm missing something, but I don't know what. Am I retarded, or are they overkill with TK?
For some reason, it seems to me that I spent little time studying inheritance, I seem to know how to work with it, but sometimes I seem to lack experience.
Are there any experts who can answer me?