I don't sure but i want to write this sentense, I don't know i can use it or not
All people have oppurtunities sometime you don't know it through in your life,
In lifetime some people get apportunity one time some people get many time
There are many problems in this "sentence".
However, you could say:
"Some people get few opportunities
in their lifetime whereas others get many."
"
During a person's lifetime, opportunities come and go, but are not distributed evenly among people"
"
During one's life, many opportunities come ..."
But "lifetime" is the best word for what you're asking about.