A Merc isn't a hero until he has gone interstellar.
What do I mean? Don't despise small beginnings. Don't fret starting local, or assume that there's nothing local to do.
Each BattleTech World is chock full of millions of people. A good portion actually have a couple billion. Many of these worlds have those populations broken out and down by levels of nobility overlords.
It's not hard to assume, in a neo-feudal society that there are generational grievances and grudges constantly leading to small, isolated conflicts. For that matter, nobles jockeying for power could lead to machinations that result in a small armored battle in the countryside somewhere.
Whether this conflict is handled by a lord's bodyguards, or some of his vassal retinues disguised as pirates/mercs, or by honest hired mercs, is up to the people styling the conflict. But, you don't need to go interstellar to start looking for trouble that may or may not pay.
You build your reputation on the planet, and if you do well enough, handle yourself honorably enough, and are generally discreet, it might not take long before you have your first interstellar contract.
