I'll assume you are asking because you want to get opinions and discuss instead of just reading articles found on google, so here's mine:
Learn PHP (+MySql). There are some other good options, but the main reason I would suggest you get started with PHP is because of two main reasons - there are tons of materials to get you started and PHP hosting is cheap and widespread.
I personally like
http://www.w3schools.com/ 's tutorials because they don't get into too much details. But you can easily google some other resources.
Don't use a framework for your first projects. You'll get more experience when working from scratch. The results will not be anything you'd smile at a year later, but if you're starting with no experience in back side programming, it's a lot better this way IMO.
And when you're comfortable with doing simple things like user authentication, database communication and so on, go through the alternatives and decide whether PHP is the language for you.