Don't learn it all. Web development is split into three areas of expertise:
3) Server side development (PHP, Perl, Python, Java, .NET and data base management, plus solid understanding of HTML and some understanding of CSS)
Pick one of these areas and focus on it. Employers are looking for people who specialize. People who are "jacks of all trades" simply don't get paid as much, and have a harder time finding jobs because they lack the specialized skills. At least that's the way it is in my part of the USA.
Certainly start out understanding HTML and introduce yourself to CSS. Once you have those down, dive into one of the three specialties. And to be honest, there is the largest demand for Java and .NET developers. I've found jobs that want PHP developers, but they occur at 1/20th the rate of Java and .NET job postings, and often don't pay nearly as much. Sucks. A good PHP developer is worth just as much as a good .NET or Java developer, but the market just doesn't have as much of a demand for PHP.