After landing in their hometown, everyone started getting teary-eyed knowing that Twilight was going to have to return to Equestria.
"We really enjoyed seeing you! We hope to see you in a couple off weeks for the semifinal in Miami!" said Rarity.
"Thanks for everything girls. I hope to see you soon. I will miss you so much!" said Twilight with tears in her eyes.
Right after saying this, Twilight stepped into the portal and headed back to Equestria where her Ponyville friends were waiting for her return.
Although there's nothing wrong with the spelling or punctuation here (on the contrary, it surpasses many fics), I'd suggest that you add some meat to your sentences. Take the first chapter for example; you mention that Twilight has received a letter, but we don't get anything describing where she is, how she feels about the letter and so on. You've got the basic skeleton, e.g. what's happening, all you have to do now is put some flesh on those bones!
Also, the chapter sizes are far too small. You've taken seventeen chapters to say just over four thousand words- that's the average size of one chapter. Like I said, things need to be fleshed out.
Apart from that, you haven't done that bad a job. I'll give a like for a pretty decent first try.
4542007
4542241
I absolutely agree with airbournesquid on the word count.
Low word counts are a warning sign to potential readers. If the Author did not care enough to write, then why should a potential reader care enough to read?
Conversely, an Author that take the [time + effort] to write a healthy word count (2000+ words per chapter, as a general average), this naturally draws in potential readers. A high word count also allows the Author to hold their head high regardless of how the story is received; because even if the reader audience do not like the story itself, most will respect the Author's [time + effort] put into the story.