1. What is pacing? For the overall story, it's the rate at which things move along, and how much time it takes to get from A to B - where A and B are anything under the purview of narrative focus, including scenes, beliefs, ideas, and characters.
Within a small block of text, it's the information density. A paragraph that takes 50 words to tell you that we're in New York* is much more slowly paced than one which takes five.
*I'm aware New York is a state and New York City is the city, but since I don't live there I'm going to wallow in this obfuscation. PS. Fuck you all, signed Chicago.
2. Okay, what is good pacing? (Small block of text edition) I'm sure you saw this coming, but it varies. Let's consider a 50-word paragraph establishing that we're in New York:
The man behind the counter shouted for people’s orders with full expectation that they knew which bagel they wanted. Given the crowd, it was probably dangerous not to know—although outside was lit