The Big Bang happened everywhere at the same time. There is no “center” we can point to as you would think of a conventional explosion on earth.
As such, the space where Andromeda is poofed into existence at the same moment that the Milky Way did (as well as everywhere else in the universe).
(And to be clear, the galaxies took time to form…the space they are in and fundamental particles is what poofed into existence.)