I'm no master at all or expert :) yes, go with w3 first and then on "what to do", try to work on a project of yours... then plan, code with future in mind. If you create a code to detect a character, try to build one who can detect "ANY" character, I mean a function, that's something you can resue in the future, then you will be building a set of useful tools and functions on your own that will help you.
Read, learn, try, test. Like... there is a great difference on loops "while X<Z.length" than using "x<5", or using loops going reverse, to ZERO. And try to avoid memory consumming techniques, it matters when you are working on something big.
Many things can be understood by "going critical" but one thing I know for sure is you create a habit and then when a lot of things are important you might pay the price for having bad coding habits. Experiment and choose a project for you, something you like, that will take the most out of you in fun ways. Good luck.