As Mario lied on the ground. of the woods not sure what had happened, wait...what did happen...all he remembers is...well nothing, nothing at all. as the groggy Mario opened his eyes...he saw two golden eyes, starring into his.
"AAAAAAAAAAAAAAAAAAAHHHHHHHHHHHHH!" Mario screamed.
"What...whats wrong?" the strange horse asked.
"Y-you can talk?" Mario asked in confusion.
"Well...yeah!" the grey winged horse exclaimed.
"We all can!" the being said.
"What's happening to me?" Mario asked the horse.
"I think I ate a bit to many mushrooms!" Mario said.
"m-mushrooms?" the grey horse asked.
"What the heck are you...you...horse...thing" Mario asked.
"My name is Ditsy doo, but you can call me Derpy" Derpy said.
"Whats your name?" Derpy asked.
"I-I'm Mario. " Mario said.
"Neat, so how did you get here?" Derpy asked.
"Well...I'm not shure" Mario exclaimed. "The last thing I remember is...well Me saving Peach" Mario said scratching his head.
"well I'm not shure ether!" Derpy said.
"but I do know somepony smart enough to figure it out!" Derpy said.
"First. we've got to round up my friends!" Mario explained to Derpy.
"Who are all your friends?" Derpy asked Mario.
"Well I've got a brother tall clumsy and green...a little red pillow an-" Mario tried to finish but.
"Wait a Little pillow?" Derpy asked.
"Yea...why, have you seen him?" Mario asked.
"yea. I thought it was an ordinary pillow...so I took it home and gave it to my daughter." Derpy said
"no it's not a pillow it's a Pi'illo" Mario explained.
"Whait the pillow is a pillow?" Derpy asked. in confusion.
"No the pillow is a Pi'illo" Mario said.
"The pill-" Derpy tried to say.
"Look...never mind!" Mario said to Derpy.
"all I know Is we need to find Dreambert, NOW!" Mario said in rage.
"O-OK" Derpy said.
"I'll take you to my house. Mario" Derpy said.
This is your first fan fiction, so let me start off with the problems.
1) You started out with Mario in Equestria instead of a fight with Fawful. I think that would have been a great way to add length to the prologue.
2) You are most certainly right; you need to work on grammar. I can't get past some of the sentence fragments, and you put a period and a lowercase word. Like 'When I found out about the problem. he tried to kill me. but I would have none of that.' Try working on the grammar a little bit; if you need a proofreader, pm me and I'll see what I can do.
3) Also, the one-liners aren't helping much. If Mario continues talking, don't put the rest of the dialogue in a separate paragraph and add a 'Mario said'. Instead, just add dialogue after the first time you put 'Mario replied'. This is what you do:
This is how it should be set up:
It makes a big difference, and it saves a few words. Always be careful when dealing with dialogue.
It's no big deal though; I'm a beginner at writing fan fiction too. I'll be glad to be your proofreader.