Simply put, humans can come from just about anywhere in the OtherSpace universe. The cradle of human civilization is obviously Sol System, but in the decades since humans got hold of faster-than-light technology, they’ve found their way to every corner of the Orion Arm.
Likely homeworlds could include:
But it’s also possible that you were a human kid aboard a freighter that got hijacked by Hekayti pirates and wound up slaving away in the mines for a while. Or your parents helped colonize a distant terrestrial world. (Wait, you may think, can I make up my own worlds?! Yes, within reason, if it makes sense in the biography. No guarantee we’ll add it to the grid, though.)
Career options are expansive for human characters, from retail work to politics to piracy. Pick something that works for your character from a story perspective. Perhaps they’re an engineer that specializes in starships. Or they could be a skilled bodyguard. Maybe they feel compelled to serve the galaxy as a journalist, telling stories they find all over the Known Worlds.
This cancer has been creeping into humanity for several years, specifically on Earth and especially among certain arch-conservatives. It is in no way required for you to create a character who has been indoctrinated and radicalized as a xenophobe. In fact, it’s probably best to treat The Dukes as more of an NPC faction. Characters who act like them aren’t liable to be very popular *except* as figurative (and sometimes literal) punching bags for the players.