I'm not the best at explaining this stuff, and quite frankly I may be wrong, but I think Lua is pretty versatile in that it's similar to a lot of other languages. The script can be written in many ways, so having any sort of programming experience would be helpful, as you can sort of "shape" the script in a style that's similar to what you're used to. If not, I hear it's rather beginner friendly too.
I also hear
http://www.lua.org has a pretty good manual.
I've never tried Lua scripting or TAS (which I assume is what you're wanting to learn about), so take this with a grain of salt. I think a forum specialising in TAS or Lua in general might be a better place to ask about this stuff.
I hope that was somewhat helpful.
