Hello! Done with your first chapter and it was really good! Your characters definitely have different voices even with just the little bit I read about them. I think you did a good job in letting their dialogue show who they were, even with just the word choice and the tone. They're all interesting characters and that, coupled with what you've shown about the world of the story, really build up this sense of intrigue to carry on to the next chapter.
I do think you might have gone a little bit too heavy with the descriptions at the start. The things you were describing were definitely helpful in building up the setting and mood, but there was a little too much too soon, especially as it was the opening of the chapter. It also felt a little off and I couldn't put my finger on why until that scene ended.
So, because the story is in first person POV the amount of detail put into describing the surroundings felt a little unnatural. Most people wouldn't notice too much about the structures around them given the situation, like the pattern of the bricks on the exterior walls, but they might notice the way the dust obscures their vision and the feeling of the grains of sand in their eyes. I think sensory details might be something that is missing while visual ones are being accentuated. Given that your background is in comics, I think it might be an issue of leaning more towards visuals. You're painting this picture for readers but you're forgetting to include the character.
Right now, we're in Jonathan's head, so what is he thinking? What is he feeling? We get a little of that at the end when he reflects on the way he feels about the other characters and it's a nice bit. It would just be cool to dig into his mind a little more deeply as we'll be in it for the remainder of the story.
Other than that, I really enjoyed it! I think there's some little issues like the dialogue tags, specifically the punctuation (using a comma instead of a period and not capitalizing dialogue tags, only action tags). There were bits that flowed a bit oddly and some sentence fragments in the second paragraph that made me pause. But yeah, in general I think your writing is good, your characters are distinct and there's definitely a strong voice that carries through your writing!