C++ is my L1 too, but I'm not good enough in it to develop commercially. What would you recommend for C++ anyways?
meh about learning programming like that...the best way to learn is to give yourself a project to make and just do it. Experience is the best thing. You can even run JS live in places like JSFiddle and etc. Reading resources is just going to go in one ear and out the other. The only thing you need to consider is how you plan to write code. Using plain javascript, using a library like JQuery or a framework like AngularJS.
Honestly just take a random youtube guide about the thing you want to do and get started, because (this sound pretty generic) only practice makes you good + you learn far more from trying, then reading. I dont know if this applies to anyone, but most of the guys i know, learned their stuff while working on a programm So yeah programming is learning by doing (of course you have to study stuff, but the most things you learning while doimg something )
learnxinyminutes for experienced programmers. Javascript: You Don't Know JS (Github) Python: Hitchhiker's guide to Python
Coursera/edx for python just audit the course if you don't want to pay for it For javascript w3schools is okay