There are many options for programming for the web. These are some of the key technologies that you would definitely want to start with. There are plenty of courses and books on these but the key is to practice.
HTML5 - markup language for structure of web page
CSS - cascading style sheets control visualisation of web pages
JavaScript - controls the behavior of web pages
CMS - Content Management System - stores web content in a database. A good tool to start with available for free is
Drupal.
Code editors
There are many, many great code editors for free and for a fee.
A good one on Mac is
Brackets, available for free from Adobe. There is a large community also using
Eclipse available on multiple platforms.
Graphic editors
Gimp is a free tool - but can be a difficult learning curve, though many learning resources on the web
Inkscape is a great free tool for vector graphics
Adode tools such as Photoshop, Illustrator, Fireworks, Dreamweaver etc are widely used in the industry but costs