When I started with Lua in 2016, I had borderline zero coding experience. Everything I've learned about the language has come from online forums and the resources below.
If you have come across resources you think should be included here and don't see them, drop me a line and let me know!
This was the very beginning for me, when I knew nothing about the language or coding in general. The tutorial I started from can be found here, and is fantastic for the most beginner of beginners to understand. The forum as a whole has been growing a lot in the last year as a resource for Lua programming in MA.
This book has been and continues to be a fantastic resource for me as I learn. The book is written by the same people who have built the language. When you buy it, you are directly supporting the development of the Lua project. And it is, in my opinion, a very well laid-out resource with a lot of good examples to help you grasp the concepts it covers.
A massive collection of resources for understanding and utilizing Lua programming, from the initial installation, to tutorials, to code samples, to links to outside resources, to extension library modules, and much more. Bookmark this page and make it your friend.
A Facebook page I've recently found specifically for Lua in MA. I'm still exploring it myself. Seems geared toward helping beginners to Lua programming in MA.
If you're going to get into coding, do yourself a facor and get a decent text editor. It might not sound like a huge deal on the surface, but once you get used to it you will find it a pain to be without. There are a ton out the, so look around. I've been using NotePad++ from the start, and have been completely content with it. It has a lot of handy features, works with color-coding any programming language, and it's free!
Check out the Twilight theme. Despite the unfortunate name, I find it to be quite easy on the eyes to work with.
If you're working on a Windows machine, this is (to my knowledge at the time of writing this) the most recent complete pre-compiled package that includes an IDE (Indegrated Development Environment; stand-alone editor capable of directly executing code. In LfW, this is the included program SciTE). I find it extremely handy to keep around to test snippets of code before throwing them in my script, and it's a lot easiser to do than continuously copy-pasting to the MA software to test one line; or worse, trying to use the built-in text editor in MA.
Bear in mind, it is running version 5.1, and MA uses version 5.3. The differences are minimal, but it is important to remember that they exist and keep an eye open.
IF you have the technical knowledge for compiling your own code, you may consider looking into the link below.
https://www.lua.org/download.html
For Mac and Linux users, this is going to be where you'll want to start from. As I do not own a Mac and am new to Linux, I cannot offer much more direct help. For more assistance, I would recommend the browsing http://lua-users.org/wiki/