I think part of the problem here is that programming, particularly in C with its huge breadth and influence, is such a broad subject.
As such, knowing what to concentrate on, and what is and is not important right now, can be daunting.
Many here, with embedded processing experience, would argue that the "do..while" construct (where the body of the loop is always executed at least once, unlike the while, or for loops, where the body of the loop may never be executed) is a waste of time.
However, someone involved in language processing, like a compiler writer, would say the do..while is invaluable, because it, like the while loop, reflects how natural and machine languages are structured, and allows simpler, more elegant mappings between problem space and program.
Some programmers will decry the ternary operator as being too terse, whilst others will defend it with second amendment zeal, because it is terse.
So, trying to find a simple, twenty minute YouTube potted C/C++ course is always going to be an exercise in frustration and futility, because such a thing cannot exist.
Furthermore, how you got to where you are now will affect how you go forward.
I have never had a C course in my life, but arrived at C from a background programming in Algol-60 (C's great grandfather) and Pascal, so many of the concepts, like scope and block structure, were already second nature.
Someone arriving at C from a background in FORTAN, BASIC or COBOL will have a different perspective, and will need some . . . remedial work.