looking here https://en.wikipedia.org/wiki/Woolly_mammoth and here https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza tells me that the last woolly mammoths died around 4000 years ago and the pyramids of Gizeh were built around 4500 years ago.

Thousands. You can check old photos of the sphinx that show clear marks from water running vertically down the walls. The last time Egypt was that wet was many thousands of years before the official age of the sphinx and pyramids

Robert schock if you want to research more