Question

How many universes or galaxies are there in outer space? How old is the oldest galaxy and universe?

Answer 1

No one knows.
The universe is around 13 billion years old.

Explanation:

There many many galaxies . Many thousand or maybe millions of galaxies.
We can't tell.
The age of the universe is around 13 billion years.
So the oldest galaxy might be around 11 to 12 billion years.