If you list all English words in an order, a preferably standard/prototypical kind of order, what will be the first word on the list?

I'd say that if nothing else is specified, then the most correct choice of putting the words in an order is ti put them in alphabetical order.

If there is "the first one of all English words", then it's actually a bit difficult finding a definition for that where the first one would be something else than "a".