Every Pokémon has individual values (iv) which makes their stats sifferent from other Pokémon of the same specie. These values range from 0 to 31 and people try to breed Pokémon with 31 iv's on the stats they'll use more. Like try to get 31 iv's on attack and speed for a Salamence. VM means "visitor mensaging" and it's posting on other person's profile.
I might join the clan in the future too, currently building on a team.