How do you understand roblox lua ? on the wiki , Its just scrambled around information about a bunch of things nothing in order , I don't understand scripting right now and how do people know what to script to make games with text above people head and etc ?
This is a very tough question to answer. Learning isn't an easy process, and you won't be able to understand everything as quickly as you might want to.
I recommend starting by trying to figure out what other people code does. Start simple, try to modify it and see what happens. Learning is all about experimenting and gaining experience, so go on, don't be afraid to check out free models and try to tweak them.
You will face many issues and code that isn't working, but try to be patient and calm and if you're really stuck with some concept, this is a great place where to ask for clarification.
Read the wiki it contains the basic Lua scripting things or study lua or scripting in school
I learned how to script by making myself start a project like a tycoon for example and then making myself learn how to script it like first i made a script that changes a value of something to the name of a player that touched a certain brick and so on :)
I'm not sure if it will help you but You can check here :) https://scriptinghelpers.org/glossary