Ash has a bunch of Booster Gold comics, but he doesn’t talk about them all that much. He tried explaining Booster Gold to me, but I wasn’t a very good listener.
I think Booster Gold is a football player from the future. He was kind of a jerk-wad, and then he decided to redeem himself. So, he stole a Legion ring from a museum and traveled back in time. With the technology from the future, he has an advantage over everyone else and is a superhero. He can probably fly or something too.