Okay, I admit, I might have gotten a bit overexcited about the relationship between the boy and his father. I was honestly intrigued as to why the father seemed to hate the boy so much or was at least unnaturally vicious towards his own son, but that’s probably just my reading too far in to things. Just keep in mind that once you get to more advanced levels, you’ll have to keep more complex things such as relationships between your characters in mind. As it is, though, you’re perfectly fine when you’re aiming for small things like Magikarp.
Your story was entertaining and cute, and the end bit made me rofl inside. Somehow. Point being, you definitely had enough to capture Easiest Pokémon like Magikarp, and maybe a bit higher. Keep in mind, though, that you’ll also have to step it up a bit on your description, grammar (well, just kinda; you can easily fix that with spell check), and a your dialogue, as well as things like character development once you get to higher levels. Don’t get me wrong; you’ve got a great start already, even for some higher level captures. A lot of stuff that I pointed out here is “ON YOUR NEXT STORY, YOU SHOULD…” kind of thing, and most of it is there just so that this entire grade isn’t full of “YOUR _____ IS GOOD ENOUGH FOR A MAGIKARP” kind of things.
Eh. It looks like YOUR STORY IS GOOD ENOUGH FOR A MAGIKARP (Cwutididthar?)
You definitely had the basics down for an Easiest ‘mon, so I have no qualms in giving this fish to you. It’s not a Goldeen, and it won’t evolve into a Seaking, but that’s your problem. As it is, this story is perfectly fine for a Magikarp. Nice job. ^.^