It's an interesting start. It did have great details in the forest area though. It's just a bit short for me. Also, you didn't capitalize any of the pokemon in the forest. It's a bit slow, but then again what first chapter isn't.
Author's response
^^ Yeah, the first few chapters are pretty short.
I don't capitalize pokemon species actually. I don't think it's grammatical, and I think capitalizing it just makes things more confusing whenever a pokemon isn't nicknamed.