I'm here just like ya asked, bud.
It was a dry land, covered with rocks and moss, and lava falling all around the land.
Here, you repeated the word 'land' twice. Most people don't like when the words are repeated. So use a thesaurus to figure out a different word for land. Earth, terra-firma, et cetera.
This land was known and Flame Tip, the place where all the fire type Pokémon lived and trained, this is one of the many regions that make up the great Pokémon World; a world totally untouched by humans, a world full of exotic creatures all alien to our world.
The first and should be changed to 'as'. After 'lived and trained', there should be either a period or a semicolon since 'this is one of the many regions that make up the great Pokémon World' is a sentence that can stand on its own.
This is where adventures begin, where the unexpected can become expected, where everything you dream becomes real.
I didn't like how this flowed at all. Instead, you could've tried:
"This is where adventures begin - where the unexpected can be expected and where everything you dream becomes real.
“Come on, your slowing us down Sal!”
Your should be 'you're'.
the Arcanine was running at a great speed, jumping every rock and magma cycle that came between his way, his long yellow mane that combined with the light of the sun, its tiger like orange and black fur made up for most of its body.
Instead of saying 'came between his way', you should've said 'stood in his way'. Also, there should be a period after 'way'.
It had four legs; which actually made it go faster.
This sentence was unneeded.
“Got you, Megakick!”
This should start a new paragraph since it was so far away from the original dialogue. And Mega Kick is two words.
he grabbed Sal by the arms; even though Sal didn’t like it his dad kept the grip.
After 'it', there should be a comma.
“Why did you do that dad, I was winning!”
Instead of a comma, there should be a question mark.
Trish said as she turned back to the normal colored Charizard that was talking to their students about the Evolution Exams.
Normal colored Charizard? And what does that look like? You should describe it.
Sal asked and started at his teacher; he didn’t really like the fact that everyone thought that exam would define if they’ll grow or not.
I think you mean stared instead of started.
Sal was always bugging him about the beliefs, which everyone in the crater trusted completely on.
Trusted completely on? You either mean depended completely on or just trusted completely.
“I’ll live this ****ing crater and make a name for myself,” Sal said and started walking out of the cave; good thing his own tail flame was enough to light it.
I think you mean 'leave' instead of 'live'.
Sal gasped on the darkness of the night, he was almost invisible, but Sal knew who it was his father.
He knew who it was his father?
I'd rephrase that. To something more like:
", but Sal knew who it was. It was his father."
He knew it was a human, they thought it that in class.
. . . I don't quite understand this sentence at all.
A teenager probably around Sal’s own age, fourteen maybe.
That's not a complete sentence. It would've been had you said "It was a teenager . . ..".
The kid had a combed back black hair, with a tan colored skin; he was wearing a white shirt with crimson sleeves and the word Aeropostal on it.
Had combed back black hair, not had a combed back black hair. And tan colored skin, not a tan colored skin.
I didn't like this story very much. I think part of it had to do with the overusage of commas that should've been periods and semicolons. Another was the description of the battle between Salazar and Fiara. Saying Salazar bounced isn't a good way to convery Salazar getting hurt on the side of the cliff.
You also need more description. What did the school look like? You never did explain it.
However, I do have to say that I enjoy Salazar's character.