This is some advice that will only work for you during a very specific time in your writing career. That is, when you start writing for the first time. So you haven't written, and you want to write. How do you go about writing your first story? Here is another list of pieces of advice in order to get you on your way.
1) Start small.
For your first story, do not plan something large. You may be inclined to want to write an epic. Maybe you want to write a novel. Maybe you want to emulate your favorite author. Whatever your decision, my recommendation is that you set your goal to something small and manageable, and then do that.
How small is small? That depends on how old you are and how good of a writer you are. Personally, I'd say the smaller the better. If you write 1000 word chapters, how about a 10,000 word book? 10 chapters, 1000 words each. That is very obtainable. That's something you can tackle in a reasonable amount of time. Only can manage 500 word chapters? Plan a 5,000 word book. Yes, I know I'm sticking on the 10 chapters, but it doesn't have to be. You can write a 5 chapter (or 5 part) book just as easily as you can make it a 20 chapter 500 word book. How you cut it up or how you process it is entirely up to you.
The important thing is that it isn't something ridiculous. Keep it in reason. If you don't, you'll quickly lose confidence, inspiration, and motivation to complete. Don't obsess about making it as big or as grand as someone else's story. Just focus on it being a project you can complete.
If this is your "dream" story, the story you really want to write into a novel... use it. There is nothing that says you can't go back and turn your 10,000 word novelette into a real novel once you have it written. If anything, once you've got that rough draft out, you can use what you learned from it to write you larger, more complex story.
2) Don't be afraid to fix mistakes, but don't start over.
This is a tricky one. Some people get stuck in perpetual limbo, constantly tweaking and rewriting their story. Some people ought to spend a little time rewriting their story. That's the advantage of keeping your story short. If you only have a story with 10 some releases that you can finish in 3-6 months, just go ahead and finish the story. Don't worry about typo's and mistakes. Then, once the story is done, you can go back and tweak and fix and finish the story. Take the time to make a finished product, then put on the finishing touches.
Too many wattpaders obsess about covers, grammar advice, and the best name for a story that they haven't even written yet. If you're one chapter in, stop obsessing about it. Instead, finish it and then move on to your next chapter. This might not work if you writing a 200,000 word epic, but if you're writing 10,000 words, you can afford to just move forward and not obsess about what's happening now. Your story will be small enough and manageable enough that you can revisit, rewrite, and not lose years of your life every time you decide a large portion of your story needs rewriting.
3) Outline the story
This seems like a given to some authors, although it's something I don't always do myself. Some people just like to write, and they want to let the writing take them where they want to go. However, sometimes, where the writing takes you can lead you into traps where you depend on deus ex machina to get you out, or literary dead ends where you just can't think about how you can keep the story interesting.
In this case, you take your story and outline how you want it to go. You can go so far as to design each character. There are plenty of free novel writing software's that let you write character sheets, settings, and organized summaries. However, even just a rough outline of, in this chapter I want things to start this way and end this way, and the next chapter I want things to start this way and end this way.
It might be advisable to not write as "chapters" so much as write in "scenes". Imagine the scene you want, how do you want that scene to start, where do you want the scene to go, and what do you want the scene to accomplish? Then move on to the next scene. If a scene ends up too short for the chapter, maybe you'll need to mix it with another scene, or just include a really short chapter.
The point being, before you get past your first chapter, you should have a rough idea of how you want your story to go, and what you want to happen chapter per chapter. If you set up a chapter as "they keep walking until they reach from point A to point B"... think about whether it's necessary to write them getting from point A to B. You could accomplish that with a brief transition paragraph, rather than dedicating an entire chapter to the journey. If you insist on including the journey, think about what you want to happen during that journey that makes it worth something. Are the people having a conversation where you learn more about them? Are they going to run into something or find something that is instrumental to the story? Ie... the hobbit finding the one ring.
4) Decide what you want to accomplish with this story.
Decide right off the bat what you want to accomplish with this story. Be interesting and fun to read isn't really an accomplishment. Everyone wants there story to be interesting and fun to read. You need to think about a bigger goal. What do you want people to think about when they finish your story? Do you want them to feel romantic? Do you want their heart fluttering about how sweet the story is? Do you want them to feel shocked? Do you want them to think about something deeper, like what it means to be human, or why bad things happen to good people? Do you want them to sit down and think about your story, or do you want them to just have a few laughs and then move on to the next thing.
Your story can be all of these things, or none of them. However, I can guarantee you if you don't think things through about what message you want your story to tell, it's going to fail at telling it. The changes in feeling and emotion will become abrupt and out of nowhere if you don't intend to bring things to that point with subtle changes early on. Or you're going come off as heavy handed if you grind in a point by obsessing about it too much.
Decide on the point of your story, and then shape your story around this point or handful of points. If you forget the message your story is trying to tell, then it becomes a disorganized mess.
5) Don't obsess about the hard-hitting scenes.
We all have our own "hard-hitting scenes". I'm just calling them hard-hitting, but you all know what I mean when I say it, because chances are as you write your book you're basing it off a scene or two you imagined in your head. Sometimes, these are the climax or the end. You imagined an event that was epic and you just needed to write a book to put these scenes to paper.
Sometimes, it's a scene that just displays an emotion. Its one cool scene that your brain came up with that makes you feel weak at the knees. Stephanie Meyer's starlight clearing is a good example of a hard-hitting scene. It's the scene that literally made twilight possible, a dream she had that motivated her to write it. While Stephanie Meyer is criticized a bit for having her dream scene and basing an entire book series off of it, the truth is, most authors have them... those scenes that are just so awesome that we can't help but need to put them to paper.
This can cause problems though, because these scenes don't always fit in the story you end up writing. Sometimes, you just can't convey the thoughts in your head on to paper in the way you imagine them happening. Sometimes, the way you imagined things happening requires so many things to be set up that you find yourself writing your story simply to engineer that scene. That's not the way you want things to fall out. Your story should never be engineered to fit in a scene. That means your scenes need to change, and regardless of how much you hate it, maybe even cut out entirely.
Some of the older audience here might remember the remake of Wild Wild West. Had great actors: Selma Hayek, Will Smith in his prime, and Kevin Kline. Do you remember the giant mechanical spider monster? How odd that was, the entire story seemed like this really weird steampunk which had little to do with the source material. That happened because the director of the movie wanted a scene with a giant mechanical spider. Why? Noone knows. But he wanted that scene and wanted to shoehorn it into any story. In the end, the most expendable movie was wild wild west, and thus he managed to get his scene. And the movie sucked.
Point being, don't shoehorn a scene in, even if that scene was the original inspiration for your story. If it can't fit, it can't fit. Don't bank on everyone loving your one scene as much as you do. Everyone sees everything completely differently, so what inspires you to write this story might be a mediocre or even a crappy scene in someone else's eyes, through the context of your entire story. So, never forget your writing an entire story, and don't obsess about your favorite scenes. Don't assume the epic scenes you write will overtake the sloppy transitions you cling to put all those scenes together. Don't make your story just a series of epic scenes with fluffer nutter in between to fill the cracks. Plan ahead, and good luck writing!