Does my story sound okay? I need opinions on how it is and what I can change.?

Question:

Does my story sound okay? I need opinions on how it is and what I can change.?

Day One

The steady sound of fingernails drumming on a desk echoed throughout the school lobby. A young girl about the age of seventeen tapped her foot softly as she waited in line. Her waist-length light brown hair was covered up by a cameo green military hat that was tilted a little to the side. She wore a pink airbrushed shirt with a cherry blossom in the bottom right corner, and a pair of dark denim jeans. She pulled her Ipod headphones out of her ears as her turn came up.
The secretary smiled brightly, “Hello, you must be new here.” She stated as she handed the girl a small piece of paper. The girl nodded and looked at the paper. She read the paper carefully and then exited the lobby.
As she walked through the hallways of her new school a strong sense of fear washed over her,”What if this doesn’t work out? What if I stand out to much?” she thought to herself with a strong sigh. A young boy about the same age as her looked up from his book just before he ran into the young girl. The boy jumped up and looked around. He stretched his hand out to help the girl up, “Are you okay?” he asked with a small smile, “I am so sorry”. The girl nodded, “Its cool.” She said as she helped him pick up his books. The boy looked over at her, “My name is Zac” he said with a somewhat shaky voice. The girl nodded, “My name is Katherine.”
Zac had dark brown spiky hair and emerald green eyes. He was wearing a white collared long sleeved-shirt and a pair of black jeans. He smiled at Katherine, “So are you new here?” he asked as he walked over to his locker. Katherine nodded, “I just moved here a few days ago.” Zac brushed some of his hair out of his eyes and looked over at Katherine, “Well Katherine I would like to be the first to welcome you to Certhill High School.” He stated with a bow. Katherine chuckled, “…You can call me Kat.” She said as she walked away. After she had left Zac leaned against the locker and smiled, “Kat” he repeated softly.
A few weeks later Katherine walked into the lunch room. She grabbed a tray and looked at the strange substance that the school called food. She grimaced and then put her tray up, “I guess I am not eating today.” She said with a smirk. Kat looked around at all of the different kinds of people that scrambled around the school cafeteria. You had so many stereotypes. There were jocks, cheerleaders, geeks, goths, and people like her and Zac, who were considered normal or average. “Normal…a word that is definitely not in my life dictionary” she thought to herself.
Kat sighed softly and the started to walk out of the lunch room. She made her way into the gym and saw more people. The cheerleaders were practicing and a few other girls were playing volleyball. One of the cheerleaders sat by the volleyball net criticizing the volleyball players. The cheerleaders went back to their spots and started giggling and pointing at the girls playing volleyball.
Kat walked pass the cheerleaders and before she could reach the bleachers one of the cheerleaders called her over, “You’re new here aren’t you? Usually I am pretty good at remembering faces.” She sated with a perky giggle. Kat nodded, “Yeah, today is my first day.” She said trying to smile.
The cheerleader twirled her strawberry blonde silky hair around her index finger, “My name is Melanie. I am the head cheerleader here at Certhill high.” She said with her same peppy voice. Kat nodded, “What an achievement.” She answered with an annoyed tone. Melanie raised an eyebrow, “Excuse me? I consider that and achievement.” She said with a hand roughly placed on her hip. Kat smirked, “Oh please, don’t seem so offended. I just saw you antagonizing those girls.” She said pointing to the volleyball players. Melanie glared at Kat, “The reason I can do that is because I am better than them.” She hissed. Kat chuckled, “What makes you so much better, your “cheerleading” skills? Please doing a few flips is not that hard.” She said with a look of frustration on her face.
Melanie smirked, “If it is so easy I would like to see you do a back flip…on the floor without using the mini trampoline.” She said showing her to the long blue matt. Kat nodded and walked to the beginning of the matt. She placed her hat on the floor and turned around, “This is a piece of cake compared to some of the other things I have done.” She thought to herself. Kat groaned as she saw a crowd gathering in the gym. She took a breath and did back flips down the entire matt, and then ending in a front handspring. She picked up her hat, “Anything else?” she asked with a smirk. Melanie frowned, “That is no big deal. It is not like I can’t do that.” She said with a small smile. One of the other cheerleaders leaned close to her, “Mel you can’t do that.” She whispered. “Shut up!!” Melanie yelled as she walked out of the gym.
Zac walked out of the crowd, “So we have a new cheerleader I presume?” he asked with a smirk. Kat shook her head, “No way am I getting g myself into something like that.” She chuckled. Zac nodded, “So how did you like the food?” he asked as the walked over to Kat’s locker. She looked up at him before opening it, “It was the best darn food I have ever tasted.” She answered sarcastically. Kat’s stomach growled and Zac chuckled, “I guess that says it all.” He remarked with a smile. Zac turned towards the door, “Well, I guess I will see you Monday.” He said looking back. Kat nodded, “Guess so.” She said as Zac exited the school. Kat leaned against her locker and smiled, “This wasn’t such a bad first day.” She thought to herself .

Best Answer - Chosen by Asker: I really love this story. So much imagery and creativity. The only thing i would suggest you alter for this is in indentation for every time someone speaks, and replacing some periods with commas after dialog (like the professionals do) like this:
“Shut up!!” Melanie yelled as she walked out of the gym.

Zac walked out of the crowd. “So we have a new cheerleader I presume?” he asked with a smirk.
Kat shook her head. “No way am I getting myself into something like that,” she chuckled.

Get it? That's usually how it's done in books; periods and new paragraphs. I guess this explains why some books are so long :) wel impressive but u know wut dont touch it its like u wrote it on a moment of inspiration or somethin dont lose that touch believe me let it be natural spontaneous Good... yea i agree with ethel though....