Should I try and draw my characters from my original story

Maybe try getting used to just drawing characters before adding the details of yours?

Well, depends on the character

For humans get used to drawing faces and bodies before adding details, that way you can get good at the outline and can fill it once happy (or at least okay) with how it looks

I hope that made sense...

And then if Pokémon it's the same thing but should be easier since some Pokémon are simpler

Okay, then yeah

What I would personally do is get used to making the Pokémon as it is before making them with your additions