@BigMax  
Here’s the link of what you’ve suggested, I think it’s not bad but every time I’ve tried to draw like this my hands began to shake furiously I don’t know why, maybe because It’s something new to me.  
https://derpibooru.org/738320

@BigMax
 
How did you guess ?  
There is not one thing that you’ve said that isn’t wrong very impressive.
 
I’ll try your suggestion and post the result  
Thanks for the help.

@Minus  
Really, you found that so helpful?  
Well, you all are welcome, I guess!

@BigMax  
Why didn’t I have you as an art teacher? Took me so long to realise what I was doing wrong when I began. Thankyou for helping out other new artists!

The impression I got from this drawing is that the lines are crisp and well defined, but they’re not smooth and sharp strokes.
 
This is probably what has happened: you drew a segments, looked at the original picture again, then continued with another stroke, paying special attention to not make the line too straight or too curved. Lather, rinse and repeat, until you finished the drawing.
 
That’s what I meant with paying too much attention to the last centimeter. That’s a recipe to miss the whole picture, making perspective or geometric mistakes, or just failing to convey the right impression or emotion to the picture.
 
In fact, those aren’t unique, flowing lines. Tell me if I’m wrong.
 
Instead, try to draw a rough sketch of the whole figure first. Really, for something like this you shouldn’t take more than 60 seconds.  
Then refine the lines, you’re using a pencil so a rubber will be perfect for that. Continue refining, put more pressure on the strokes as they become definitive, and voila, here’s your Applejack!
 
That won’t look like Price’s AJ much, probably, but she’ll be your Applejack, with a bit of your style.  
And even if you think you screwed up, that’s fine. It’s still experience. Don’t even bother to erase it all, just start again… you’re just sketching after all, aren’t you?

@BigMax  
It is ok.  
It’s more than bed time for me to.

@softland  
I’ll elaborate but… not now, I’m going to bed. Sorry.

@BigMax  
“you’ll have to draw your own ponies”  
I know, but I don’t think I ready right now.
 
“you’ve been paying too much attention to the last centimeter that came out of your pencil, and you missed the whole picture.”  
Can you elaborate I don’t understand what do you mean by that.
 
“Next time, even when copying, draw a rough sketch first, then refine the lines.”  
By that you mean that I draw quickly then refine it ?  
I’ve just begin to draw a few days from ago so I don’t really know where to begin whit.
 
Thank you very much for the help you’re providing.

My comment is that you can copy the work of other artists to get accustomed with the shapes and all, but start you’ll have to draw your own ponies.
 
There’s nothing much to say here. The strokes are insecure, you’ve been paying too much attention to the last centimeter that came out of your pencil, and you missed the whole picture.  
That’s why the shapes are so skewed.
 
Next time, even when copying, draw a rough sketch first, then refine the lines.