There are a couple of routes:
1) The best is a course - because if you don't understand something, the tutor can rephrase or explain differently until you do.
2) The second best is a book - it provides all the information (and there is a lot) in a structured and ordered manner, starting with the basic stuff, and working up through data structures to GUIs, databases, communications, and so on. Start at the beginning and work through to the end, doing all the exercises.
Addison Wesley, Wrox, and Microsoft press all do good ones. Avoid anything with multiple exclamation marks, or "in nn days" in the title.
3) Grab a copy of a compiler or IDE (Visual Studio is probably the world's best and it has a free version) and guess what you need to do, try it and see if it works. This is generally spectacularly poor way to do it, as it means that you don't know what is there that might make your life a whole load easier. But it has one big advantage: it's better than option 4.
4) Dive into YouTube and start watching "C++ training" videos. YOu will learn nothing, because the vast majority of them are created by people who don't know how to teach, don't know how to make a video, and in most cases don't know how to code either. Remember that YouTube is about monetization: "likes" and "Subscribes" are what the videos are there for. There may be good ones in there but they are buried under a mountain of dross.
When you have got into it, practice, practice, and practice again - it's the only route to competance!
This may help as well:
How to Write Code to Solve a Problem, A Beginner's Guide[
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