It takes 3 months to get okay with something. 6 months to be decent. 9 months to be like, okay, I kind of get this, and then at the end of the year you'll probably change your mind and try something else.
I tried PHP, it was easy. Too easy. Hated it.
Tried Ruby, then Rails came on the scene and it became cool. Ended up hating it too.
Now I'm on Python. Learned Django. Tolerating it, but switched to Flask.
What I really want to master is JavaScript, closures, then node.js and AngularJS.
Just start. You can switch after. And to be real, making websites is actually really easy with any of the languages. Whatever you're thinking of doing there's probably already ten other projects on Github that has redone what you're thinking of that you will end up using.
It's the deploying, that perfect minute customization that you really, really, really want, scaling, and long term maintenance that's going to be tough.