Lois McMaster Bujold’s Vorkosigan saga is a space opera classic. There are wormholes and space battles and currency discrepancies between worlds. This book, The Warrior’s Apprentice, is about Miles Vorkosigan who doesn’t get into the Imperial academy and then sets off to accidentally create a mercenary company.
It’s exciting and fun and there’s actually a bit more darkness in terms of war crimes and consequences than I’d expected. I was a little surprised at the shying away from depicting the climactic mercenary battle, but it followed that up with some interestingly manipulated politics to get Miles out of a treason charge, so that was pretty neat.
I think I own a couple of Vorkosigan books but have never read them. I only started them now because Baen made nearly the entire series available as free ebooks so I could bring the entire collection on my winter travels. Which is pretty enjoyable.