The First Age is our age. I am assuming a vast, massive cataclysm to end the Seventh Age and reset the Wheel which would make the War of the Shadow look like a playground scuffle, so the idea of any stories or legends like those Thom tells Egwene about the Apollo moon landings, Mother Teresa and the Cold War surviving that seems unlikely.

My theory has always been (and the world book seems to lean in this direction) that channelling the One Power is the product of genetic engineering, which we are starting to see now. So channelling appears in the late 21st Century, and is probably used as a weapon until the channellers themselves rebel against its use and establish a new world order of peace and prosperity, thus becoming the Aes Sedai. During this period, in our near-future, they build the portal stones. They encounter the Ogier during these explorations of other worlds and the Ogier move to our world.

We then move into the Second Age, the Age of Legends, thousands of years of peace and harmony in which the meaning of the word 'war' is lost. Then the Dark One's prison is discovered, full-scale war breaks out etc. We have the Breaking, the Third Age (the Age of Prophecy, according to the EotW UK paperback cover blurb, though never called that in the books) and thus into the books. The Ogier vanish at some point in the future of the books, as does channelling, and the world resets itself to the First Age and so on.

As for the numbering of the ages, this seems locked in place. Both in-universe characters and the out-of-universe narration (including comments by RJ) refer to it as the Third Age of seven. That seems fairly certain.