When writing a story, always remember the main points, you should have an Orientation, Complication and a Resolution. You don't need to plan further ahead if you're rushing through your work. Never rush through your work unless you have lots of experience.

Take your time so your brain can progress when thinking, if you're rushing, you're mainly going to get head aches and stress. Especially when you're all over the place currently and is suffering through a writer's block. You don't want to have your information about your characters all over the place, no?

So when you're writing your story, take these into consideration;

Orientation - This is the important part when writing, you need to introduce your characters. The characters that you are going to introduce should be your main character(s) first. When introducing him/her, add a setting, and optional, time. This gives the reader a better image of the start of the story. If you're going to introduce your character during a school day, write that she's waking up in her room or having breakfast at 7 o'clock. Something to let the reader know what's happening. Add some sound effects such as "BANG", "RING" and "CLASH". It allows the reader to imagine while reading, imagining that they can actually hear the sound. This should add in personality if you'd like to spice up your writing style to fit a certain age group. Just don't use those sounding effects too much or you may annoy the readers.

Afterwards, introduce the minor(s), don't introduce all of them in one paragraph, allow some to appear later during the story (1 - 4 people being introduced in every new chapter -  The shorter, the better. This would allow your readers to get familiar with who's who. If you're introducing a group then it should be fine).

Also, describe the person a little bit to give a better image. Add in some troublesome people in the setting, like "attention seekers" in your class, to give it a more realistic feeling. This may be your antagonists. 

Follow the rest as a normal day. The orientation should go for 3 chapters or possibly more, it should contain enough information for the reader to understand the casual days.

For example:

It was an early morning and Jessica slowly rose up to sit lazily on her soft, plush bed. Her long hair was tangled to her distaste, but a new day was calling for her. "Good morning..." she mumbled to no one in particular as she quietly dragged her slim body out.
Placing her feet onto the cold tiles, she clicked her tongue and scratched her auburn hair. "Another day of practice with the girls," she murmured. PING! Turning her head to face her vanity table where her iPhone sat, she made her way over.

"Good morning Jessica! We hope to see you soon at the studio!" her band member, Tiffany, greeted. Smiling to herself, Jessica's phone vibrated a few more times, signaling her that the others were also awake now.

Complication - In the middle of your story (Around Chapter 4 and goes till chapter 7-8 or so), start to add in a problem. Don't allow the problem to start straight away, allow the problem to get gradually big. The complication isn't that hard, it can be almost anything, that would make your character feel sad or depressed.
Describe the problem in every chapter, explaining what's happening in the story. When writing a complication, don't give the answer out properly; you want to let your readers think about who's involved with the situation, e.g looking for the creator of the harsh rumors. Let the reader feel like they're actually there by explaining how the character is feeling (Remember to use good vocab). After that, (around chapter 7), the answer can be given out, explain why this problem occurred.

For example:

Justine was pushed onto the floor roughly. "Go and die you attention seeker! No one wants your face in this school!" Geena hissed before spiting her gum in front of the poor brunette on the floor. Justine didn't know why all of this was happening to her, but she couldn't gather up all of her bravery to ask.

"Why are you so... so pathetic? How did you even get accepted here?! No one wants you!" Geena added before whipping her hair to the side. Sighing, she watched Justine slowly get up from the floor. "Just die already," she whispered painfully before walking away, leaving her ex-best friend to suffer through the rumors of hate by herself.

As much as Geena hated it, the rumors surrounding Justine was slowly involving her. She hated it. There's nothing more fun to do when your best friend is no longer holding onto that title.

Resolution - You want your characters to solve the complication. Such as telling the school about what the antagonist has done, and let the girl be expelled from the school, or the protagonist going to another school. You need to allow the characters to solve the problem properly, don't write, "In the next day, they solved the mystery" or something along those lines.

That wouldn't make sense to the reader, explain what they did carefully, and slowly lead the reader to the correct setting. Doing something blunt like that would only make the reader dumbfounded. So explain everything!

The resolution can then be ended in any possible ways. This is where you may want to slowly close off your story,

For example:

Jaejoon grabbed hold of the microphone on stage and looked directly into Hyuna's eyes which were filled with shock. Taking in a deep inhale, he turned his gaze to look at me. His eyes were passionate and loving, and they were only for me to see. Sighing in relief that he still had faith in me and not believing in the rumors, I gave him a questioning look.
"Yuna is innocent. She did not spread out those rumors to annoy the school - In fact, you guys are all merely blind for not looking into the truth. Why would our loving, innocent Yuna be telling us all of these lies in the first place when she has all of the support from you guys? You all believe in Hyuna's lying words. Yuna did not spread the rumors, Hyuna was," Jaejoon announced as he soon accusingly pointed to Hyuna in pure hatred.

Gasps were all around and soon the assembly was filled with nothing but rumors. The teachers were far beyond outrageous, and the school members were disgusted at Hyuna, but not only her, but were disgusted of themselves for not believing Yuna. 

When writing a story, sometimes reading a book can give you ideas. Using another text can guide you through things when writing. Just don't steal other people's writing piece and claim it as your own because that's plain mean and plagiarizing. So copying is a no-no.