So the universe is mostly Conan the Barbarian. Magic is few and between, mostly hostile, and it's sword and sandals. The most advanced piece of tech is either a piece of good steel or windmill. One day, an airship appears and floats towards and over a city. The city's already been warned that it is arriving and what it looks like, but this is also the first time they've actually seen advanced tech, and haven't quite internalized the concept of 'flying giant ship in the sky'. Also, it's a ship for commerce and starting up trade deals. It's also bigger than the Hindenburg.
I would imagine that it would be like those giant ships in Independence Day. Or, more likely, it would be seen as a giant cloud of some sort ... the only large airborne thing that any of them had ever seen.
Many years ago, my wife and I took a road trip across the US of A. There were a few absolute unarguables, including the Grand Canyon. We all know the Grand Canyon, we all know it's awesome but I remember feeling nervous as we approached that it couldn't possibly live up to the hype. And then, standing at the rim and feeling my breath taken as the views surpassed anything I preconceived. Something akin to that for your characters knowing the airship is coming and then seeing it for real.
I imagine a lot of superstitious dread, people dropping to their knees and either worshiping it or crossing themselves (or whatever they do to ward off evil magic in their society). No arrows I assume? Cause it could be really bad if there are.
Politicians and Priests (possibly one and the same in your world?) would find ways to take advantage of it. As they say in the upper echelons of Governance "Never let a perfectly good crisis go to waste."
Youtube videos of the old german blimps. That should give you some good references. You can also look up people flying on a plane for the first time. Between those two, you should have what you need.
I've a touch of megalophobia--abnormally large things sort of freak me out. I once saw a flag that had no right being as large as it was. This thing was as big as a Walmart, flapping in the wind like some great big omen. I didn't want to take my eyes off it, kept shifting my gaze back and forth between the road and this monster flag. It felt violent simply because of it's size. As if it might decide to unhinge itself from it's pole and smother everyone driving by with it's great big stripes and stars. A big fear of mine in being in the water with a big ship nearby. Sounds terrifying and I'm not even sure why. It's just it's SIZE that's terrifying, nothing specific like being run over by it. Of course, I'm not going to start screaming or anything. So if I saw a big airship, I'd look like one of those frightened bunnies you accidently stumbled upon--big, nervous eyes shifting around and prepping my muscles to run at a moments notice. Might even cling to someone in a death grip, getting ready to fling them as a sacrifice so I can run away.
