2) Yes. Personnally I learnt Lua while discovering and documenting Nspire Lua. But I'm not an example. On the other hand, learning a language is hard without a goal/project. Your goal : understand how Lua tables and meta tables work

3) You have the choice. So the question is "do you have time to learn completly Lua before learning the extra-functions of Nspire Lua ?" . If so, start open the huge
Lua documentation and read it from begin to end. Same for
lua-user documentation. Otherwise, use
Inspired-Lua starting tutorials4) What is a simple program for you ? For example I made in two days
Nyan Cat. Two days is really short I think and a normal person will make it in 5-6 days. Give an example of what you think to be a "simple" program/game.
3 I don't think i have time to learn Lua completely (busy with school and stuff) but ofc i don't know how long that takes. so how long do u think to learn it (and it's it irritating to learn Lua first and then nspire Lua which seems to be a bit different)
4 by simple program I mean something like somethig that isn't just plain text like hello world but some action(and ofc as start not very large to make ) and what do u mean by days 24 hours or 8 hours ?