I'd avoid PHP (because there's so many that start from scratch with PHP and make a bad name for themselves and the language). Python and Flask are a good place to start and Python is a "respected" language. So without experience and PHP on a resume puts you'll be lumped in the same group as all the awful programmers that think PHP is bees-knees (Even if you're not awful).
In general though as long as you learn good learning skills you'll be fine. It doesn't matter what framework you choose in two years or less the stack will be very different (with a high likely hood). Learn good software design, databases, cacheing, javascript, basic html, css and you'll be solid no matter the details of how it's accomplished.
Plus, there's this. http://me.veekun.com/blog/2012/04/09/php-a-fractal-of-bad-de...