Learn object oriented programming, using Java or C++. That will give you a strong basis for almost anything else you want to do (I used to be a C++ programmer, and was hired as a Java programmer in spite of having no Java experience, on the strength of the C++).
if you want to do web stuff, learn a little HTML and CSS - you don't need to become an expert because most companies have people who specialize in HTML and CSS. You just need the basics so you can understand and modify pages. Also get familiar with HTTP.
Most professional-grade sites are built on CMS's. Drupal is quite popular. Learn that with PHP and you should have a leg up.
Be prepared to keep learning new technologies constantly. Things are changing quickly, and even if you establish yourself as a PHP or Java programmer, new libraries are always popping up that you'll need to learn.