What is the shape of space?
While we don’t know the answer to this question, we can make a pretty good guess by looking at how galaxy’s and solar systems form.
Most likely the formation of the universe follows a similar pattern. Unless there is an unknown and as yet immeasurable force outside of the universe effecting it’s formation.
Our universe is likely only one of countless universes floating in the cosmos like massive cellular structures. Which makes the entirety of space so huge that we will never be able to form a system of measurement to define its size.