Why is there millions of galaxy?

Answer 1

There are probably more. Space has no end so there is infinite space for galaxies to exist. We only know about the part of the universe closest to us, we might one day find trillions of galaxies in so far unknown parts of the universe.

A2. Astronomers estimate there may be at least 10^11 Galaxies in the Universe, and each Galaxy may have between 10^7 to 10^14 Stars. Say an average of 10^10. Some of which will have solar systems.

[For convenient typing, I use the caret mark ^instead of using the superscript.]

In addition, current thinking is that about 90% of the universe is Dark Matter, about which we know almost nothing. But that would only add a couple of decades (10^2) to the above numbers.