I learned what little lua I know by reading over existing lua scripts to figure out how they work and then tinker. I know that’s probably not a good idea for someone with 0 programming experience (myself) but it’s what works for me.
Youtube/Google helps if you have questions on certain lua things, and GD has a ton of existing lua already that you can get an idea for.
There’s also a modding guide that has a decent write up about many lua features and how they should be used, plus there’s a lua API on the forums somewhere that can give you some info about variables and stuff.