A lot of people who make guides on Wattpad simply skip over dashes. Not because they aren't important, but — and this I'm assuming — they aren't as commonly used as some other forms of punctuation (like commas). I don't know why, but don't limit yourself to just not using them because of this. The biggest problem with dashes is that many people don't know when to use them. The first thing you should know is that dashes are always optional. You do not have to use them. In many cases, elipses, commas, or other forms of punctuation can be used too. They provide another format that you can choose from. I'll go over all the different times that you might use a dash.

Often dashes are used to re-direct a train of thought or interrupt you in the middle of a sentence. The interruption may or may not be relevant. A lot of the time the dashes are used to insert a full sentence that does not flow with the main one or doesn't work after. Still, there is a lot of leeway when it comes to dashes: you can have incomplete or complete sentences, for one.

Example #1: It was a dark and stormy night — I don't remember the year — and everything in the house echoed with the sound of thunder.

Or...

Example #2: It was a dark and stormy night and everything in the house echoed with the sound of thunder. I don't remember the year.

Notice how much better the first example sounded? The part set off my the dashes emphasizes the point, which brings me to my next topic (after part b of interruption).

Have you ever noticed how in books characters are often cut off in the middle of their thoughts or sentences? These are implemented through dashes. Remember that there is not a space between the word and the dash in this case.

Example:

"That's not what I—"

"I don't care what you have to say about it! I'm done talking to you," he interrupted me.

If you are a new writer (which might explain why you are reading this book) or if you are someone who doesn't care too much about writing (if so, what the heck are you doing here? Get out!) then you might think that all writing is is slapping words on a page with a few characters and maybe a couple good plot twists here and there. Although that, technically, isn't untrue, it is so much more than that! One of the main parts of being a writer is communication. How you tell the story. You may have an awesome plot, but it won't do you no good if you don't have the slightest clue on how to write it.

Writers use emphasis. They emphasize their points in unique ways that attract readers' eyes to the page. One of the tools they sometimes implement are dashes. If you have a piece of information that you want to stick somewhere in a sentence, but can't quite incorporate it without making it separate altogether, consider using dashes.

Example #1: Janie knew which cat she wanted as soon as she saw the fur — bright orange like the sunset — and leaped over to it, triumph bubbling in her chest.

Example #2: She was my best friend — my only friend — and I was terrified at the thought of losing her.

The first example is more informative. It shows the readers how Janie is viewing the cat. The second is different. This one is an excellent example of emphasis. In just a few words, it outlines the desperation of this person losing her friend because you find out that not only is she her best friend but her only friend.

I touched on this in "emphasis" but I'll clarify it for you. Sometimes all a dash is needed for is that extra burst of information the writer decided was necessary before the reader finished the sentence.

Example: Britney — the girl who claimed she came from another realm — sat mysteriously in the corner with a sly grin turning up the corners of her mouth.

The part of the sentence that is separated by dashes is necessary for you to understand why Britney seems so mysterious! Dashes can help you do this.

Those are the three main uses for "em dashes". You probably noticed that there are two dashes side by side when you try to use them. If you are using them on word, this shouldn't happen. When you are editing a chapter, they will show up separate but when you post them, it should be fine. Many authors do not put spaces between the words and the dashes, but you can if you want, like I did. It is really up to you. If you are on Wattpad, you also may have noticed that some people only use one dash instead of two. This is actually incorrect, but most of the time people won't call you out on it.

Example #1: Jean and Susie — his trusty sidekick — leaped over the fence.

Example #2: Jean and Susie—his trusty sidekick—leaped over the fence.

Example #3: Jean and Susie - his trusty sidekick - leaped over the fence.

I hope that this answered all of your questions and helped you out! Thanks.