Some stories are fast, or just straight up rush or are slow, or nothing really happens. Many words may be just filling bloat.

I will not tell you to write slow paced or fast paced. Different readers prefer different pacing speeds, and depending on what you write, a slow pacing may work better than a fast pace.

Now, pacing describes in what speed the plot progresses, how fast, or slow, events build up, when they happen and how long the climax is in effect.

Slow Pacing:

I for my part don't like it. And I can't really write it. But so do other folks. Some people equate a slow pacing to 'nothing happens' or long breaks between shit happening. These books are bloated with filler to appear long. These move as if two snails would push a third one.

The truth is, slow paced works may take their time and leave the reader time to breath from 'action'. but things still happen, but these tend to be more small scale. That's why fast paced books are more commonly stuff that isn't action heavy. These may be mysteries, thrillers and romances that aren't using the sin of insta-love. In terms of fanfiction, I found a rather well written fanfiction that was slow paced. It seemed nothing was happening, but in truth, the main character, a sinister genius, was just slowly and carefully setting up things for their master plan. Which included manipulating people and collecting data. (I discontinued because it was a Tomarry Fanfiction, disgusting pedo ship.)

The opposite is the fast paced story. The reader has lesser breaks from action and things may take lesser time to be set up. Some people just write events back to back, that the plot becomes a chaos of events, no time to breathe. They are often incoherent and you can't really immerse, because as soon as event X started, it already ended. Things progress so fast, you didn't really realize they happened. This is called rushing, the reader then has no real grasp on what had happened. The pay off also feels lesser earned. A problem often plaguing insta-love stories, but these are bad for their own reasons. Some people make their writing fast paced via many time skips, but that makes it just harder to follow and makes the writing look incoherent.

Both sides have their pros and cons, so I can't and won't say what to do. I just tell you to avoid doing the mistakes that ruin these placings.