I'm relatively new to actual LaTeX scripting, much of my experience comes from using MathJax over at math.stackexchange.com and I'm kinda self-taught, just picking things up as I need them. However, I'd like to write an entire paper in LaTeX now and I need to do a bit more than MathJax offers to me, such as page allignment, font selection, etc. However, it would be nice to view a list of all (or most) the commands, preferably categorized and easy to navigate. Does such a place exist and where can I find them?
I don’t know if there is a list of all commands available, but there is at least the Comprehensive LaTeX Symbols List. You have an exhaustive reference of mathematical and text symbols for a wide range of packages.
For the rest of the commands, the package documentations have an index of the commands defined. Maybe it is possible to parse the PDF files with a custom script which will make a more accessible list.