Ezra's planet has been conquered and enslaved, but Ezra is one of the few still able to resist. Ezra is a human. We get flashbacks of his family in some of the episodes, but do we know how old Ezra is?
Physically, Erza is around 38 (the same age as the actor who plays him).
However, his actual age is difficult to determine. Ezra actually died when the Aliens invaded, and has been revived some 400 years later.
The series takes place 400 years after the human race has been exterminated by aliens. It follows Ezra, Abram, and Feena who have been revived by an alien faction for the purposes of restarting human civilization.
And from the plot to the pilot episode:
After the human race is wiped out by a mysterious alien force three humans, Ezra, Feena, and Abram, are brought back to life 400 years into the future by the mysterious Red Drone.
If you take only the years he has been alive, then he's around 38. If you take the years since his birth, then around 438.