Hello folks, I've been out to about 800 LY from the starting position system, at about 200 LY I saw the last space station, and from there space is EMPTY, no living or mechanical soul out there. Is the inner orion spur the only inhabited sector in the whole ED galaxy or what?
Yes.
You will often hear people talk about "the bubble". They're not talking about the Bubble Nebula, they're talking about the relatively small region of space within which the vast bulk of humanity lives. 20,000 star systems, 7 trillion people, all living within about 200 LY from Sol. There are a few outposts established within the last 5 years, but apart from those, there are very few outposts outside of the Bubble.
If you want a "lore explanation" for why human space is so tiny: the Frame Shift Drive that allows virtually instant travel between star systems was not invented until very recently, like the 3290s or something. Prior to this, interstellar travel required a "hyperdrive". Hyperdrives were much slower and less reliable than the FSD. It took a whole week to travel a single maximum-range jump; the fastest ships could do maybe 32 LY per week? On arrival at the destination, the hyperdrive also dumped you 10 AU away from the star, rather than literally right next to the star; that's roughly 5000 Ls away. No Supercruising back then (Supercruise uses the FSD), so if you wanted to refuel to make the next jump, you had to spend another week accelerating and decelerating through normal space to the star to refuel, before making the next jump. So it's really 32 LY every two weeks. Finally, hyperdrives were cantankerous things that tended to explode and leave you stranded if you didn't do regular maintenace (at least once a year).
The upshot of all this was that it was physically impossible for a lone unsupported starship to travel more than 1000 LY from civilizaiton, as it took 6 months to get out that far, and six months to get back again before your hyperdrive died.
