I'm sure you can find proper documentation for Lua I remember coming across something like that, I'll try to look it up for you:
Ok so it took me like 5 seconds:
http://www.lua.org/manual/5.3/
Yes it is annoying, but if you want to be a programmer better get used to it soon, you will read a lot of annoying documentation.
If you want a language that is well documented for beginners PHP could work. But I would advise you to try javascript instead. It should also be well documented. You can try javascript code in your browser console (F12) or install node.js.
PS: C++ is the mother of all languages, if you can stand the compiler and cope with the APIs (or are happy writing 70ies style console applications).
How about Java?