does this mean that one gets to a place/event and realizes that they are early, or that there is a requirement for them to be early to a place/event?
Only the latter (gá is “requirement”). The former would use a different structure, e.g. Caithfidh go bhfuil mé go luath.
@AnSeabhac, There is a requirement for me to be / that I be early = I have to be early
So there's no difference between saying "bheith" and "a bheith" in this example? When is one used over the other?
Sorry, I did not notice the "a" in your question (I'll blame my inattention on the phone screen...)
But I think you still gave the right answer.
Is gá dom bheith luath - "There is a requirement for me to be early" Is gá dom a bheith luath - "There is a requirement that I be early"
There isn't really any difference in meaning, though a bheith is used for a dependent clause, whereas bheith is usually used at the beginning of a sentence, and in this particular sentence it may just depend on how the writer is used to speaking the phrase.
My first response to this question was " I have to be early" and it was incorrect. But when I gave "it is necessary to be early" I got" I have to early "as an alternative". What is this about?
This sentence bears an uncanny resemblance to southern US patois: "I got to be early".
"I've got to be early" isn't that unusual in Hiberno-English, but any resemblance to "is gá" is purely coincidental.