Planning to rewrite this resource some. Just putting it out there. I haven’t had the time to address the shortcomings of this post and so I dearly apologise. Follow the conversation in the responses below.
https://www.lua.org/pil/contents.html
For a bit of time I’ve been thinking over this. There’s been many threads on the DevForum asking where a good place to begin exploring Lua would be or where they can find documentation to help them along their learning path. There have been mentions to the Roblox Wiki, video tutorials and obscure mentions to PiL - but there wasn’t actually any dedicated thread to PiL. That’s when I thought to make this thread to share PiL so that it’s accessible to you without needing to search too deeply or come across it by chance. Just open the Resources category and wham, here it is.
The link I posted directs you to the online version of “Programming in Lua” on the official Lua website. Though it is mainly aimed towards Lua 5.0, it still holds major relevance and has the necessary know-how for you to program on Roblox. The code you write in Roblox Studio is a sandboxed version of Lua dubbed “RbxLua”. Most of what Lua has to offer is available in Studio, as well as Roblox-specific implementations. Any number of resources out there can help you all the same, but if you’re starting from zero, this may just be the hand you seek.
If you are looking to learn Lua but are unsure of where to begin, this would be a good place to flip through. It covers the basics and works it’s way down to advanced practices. Depending on your ability to comprehend the material it may take a few re-reads or questions before you understand, but at the very least you will be able to understand some things about Lua and perhaps start on basic programming.
This is not to say that you shouldn’t also read the Developer Hub’s articles or anything on Roblox’s Medium page. Both of those respective resources have amazing articles on specific subjects and also help towards such learning. PiL can help you to understand Lua concepts and tease you into exploring the awesome world of code.