Any of what you mentioned will serve you well. I'm a Django/Python developer in my day job. It's an amazingly good place to start. I use python, html, css, and javascript on daily basis. JavaScript is another option and the one I'd highly recommend. Go to www.nodeschool.io learn node.js and javascript, then learn more javascript for the client side along with html and css.
All those things you listed are relevant, go build something it doesnt matter where you start but where you end
If you want a complete nuts to bolts introduction to web development, I'd recommend starting here:
http://prework.flatironschool.com/web-development/
It's ruby specific, but what you learn in terms of html, css, and git can be ported if you decide to use a different backend language later down the road.
Then just start building things - that when you'll start to really learn.