Can't seem to get Lua console to do anything

[CivilizationAce]

I'm trying to test lua through the console, but I can't even seem to get the simplest stuff to work. Right now I'm trying the following

print(Players[0]:GetName())

I get the error message

Runtime Error: [string "_cmdr = {print(Players[0]:GetName())}"]:1: attempt to index a nil value
stack traceback:
    [string "_cmdr = {print(Players[0]:GetName())}"]:1: in function '(main chunk)'
Lua callstack:

I'd ask about Players or about GetName, but I can't ask about all the specific stuff that I need — we'd be here all day.

Instead I wonder if there's some generic flaw in my approach, like do I need to prefix Players with something, because almost whatever I do I get the "attempt to index a nil value" error.

I also wonder if there's a Civ VI (rather than V) lua reference.

Also is there a help command from Lua Console to query command syntax?