The Four Noble Truths, the Eightfold Path, and the Three Gates

I am no Buddhist, but have meditated, practiced various yogas and martial disciplines, studied shamanism and other paths long enough that I recognize truth when I see and feel it. The “Eightfold Path” book came out of a drive to see if a work of “EC” style stories could conceivably be a contribution to a philosophical tradition.

My understanding is that when the Buddha received his enlightenment, his first teaching was of the “Four Noble Truths”:

1. There is suffering