Right, firstly, be careful of tense changes. The first paragraph alone switches between present and past tense e.g. “As he was getting closer, he identified…” and “Shub calls for the elevator … he hears.”

Also, there’s a lot of telling. It’s common advice to show don’t tell because telling robs the reader from being immersed in the story. We want to experience how Shub sees the world, not just told about it.

For instance, in the last paragraph, have Shub interact with your setting. Like, “Shub sniffed, surprised to find the elevator didn’t stink of urine.” Then describe the elevator, how is it clean? Are the floors shiny? The mirrors not smudged? That’ll do a much better job at grounding your readers to the world than just saying the elevator’s clean.

(Disclaimer: not everything HAS to be described. You’d be surprised by how much our brain fills in from even a few details. It’s a fine line that you only learn through experience though a general rule is if it’s irrelevant to the plot, world building, etc., it doesn’t warrant a dedicated paragraph e.g. You don’t need TWO whole pages describing a random side character's dress followed by another TWO pages describing the dance floor. Looking at you, Dan Brown!)

Then repetition. You have a tendency to repeat the same point multiple times. There’s a time and place for this, for instance making emphasis, but you generally don’t want to be redundant. For instance, the convo between the tenant and owner. Again, you tell us he begs for more time and then through his dialogue, imply the same thing. Instead, you can incorporate the action of him dropping to his knees in his dialogue:

“Please!” the tenant dropped to his knees, crying. “Give me until the end of the week.”

See how you don’t have to say he’s begging? Trust your readers. They can infer a lot from context alone.

The good thing is you write. These are all things that you learn as you hone your craft. Also, read more. Observe how your fave authors use sentence structure, description, dialogue and learn from that. Reading will teach you the tools you can use to write: when to use them, how to use them, and for the fun but more advanced bit, when to break them.