Question for professional C++ programmers

Question

It's interesting to know what part of whole C++ language is represented in Sololearn lessons(in %. when 100% is knowing all main concepts needed to be first level programmer, not counting experience & knowing by heart libraries )

Answer 1

The course is good,

when you make code based on the content.

Answer 2

<5% The course is just ... meh...

Answer 3

Obviously, it's good to start with the smallest and the guidelines.

Answer 4

You don't know which problem to solve?