the final number of Pokemon in the Galar dex is 502
Scorbunny's last evolution is pure Fire-type, Grookey's is Grass/Fighting and Sobble is Water/Electric
some new Pokemon to get Galar forms are: Lapras, Torkoal, Lopunny

As for the story
Chairman Rose is the villain. He has been rigging Leon's matches for sponsorship
Oleana knows about this but can't do anything as she's been blackmailed
Team Yell is a group paid by Rose to follow Marnie around and pretend to be their fans. She is Rose's daughter
Leon is unaware about his title being a fraud and all matches being rigged. He thinks he has a lot of talent but actually he's a mediocre trainer
There's a bigger villain behind the scenes related to the legendary Pokemon