Tl;dr - the subject is enough. For background, read below.
I am a professional, freelance, embedded software developer. I first learned about C++ in the 90s and taught myself from a book C++ for C programmers.
The beauty of that was that it assumed that I knew C and didn't have to spend chapter after chapter explaining how to declare a variable/what a variable is, function/passing parameters/returning a result, loops, etc, etc, etc.
So, it cut quickly to the chase and I started learning from page 1, rather than skipping forward.
Fast (?) forward a few decades, and I no longer code (much) assembler. Work seems to be split between C, Ada (mostly for defence) and C++.
It has been four years since my last C++ gig, and, industry being conservative does not adopt new version of languages for some time, until they can be seen to be widely accepted as stable (if any of you non-industry guys what to know why, then we generally want to wait until "they get the bugs out of the new compiler". Given that a lot of embedded can be life-critical, you can understand why).
So, now I am seeing ads requiring C++ 2014 and 2017 (and my latest experience is 2003). The delicious irony of this is that I know, from bitter experience, that coding standards will forbid me from using the new features intruded in those versions.
All of my life, I have taught myself new languages & concepts from books. Earlier this year, I took a leap of faith & taught myself Flutter/Dart (for personal, non-professional use) from a Udemy course. That was an eye-opener, and I won't be responsible for the death of any more trees in future.
But, I digress (this entire screed has been a digression, if you ask me). I have now purchased another Udemy course to learn C++.
And, finally, after all of that, my question is still the same as its title - "I know C++ 2003 How to start learning C++ 2017 ?".
Do I watch the start of each chapter, and skip if I yawn? Do I read the table of contents and take a stab at where to jump in?
Given that you are a group of educators, I imagine that this is not a new situation to you, but am not sure that it has an answer which does not involve the length of pieces of string.