If the user is attacked by a direct attack, the attacker has a 30% chance of being afflicted by either poison, paralyze, or sleep. Grass-type Pokémon, Pokémon with Overcoat, or Pokémon holding the Safety Goggles are not affected by Effect Spore.
Hidden Power's power and type vary depending on the individual Pokemon using it, ranging between 30 and 70 power. There is no way to change a Pokemon's Hidden Power type or power, so you are stuck with what you have. Hidden Power is always a Special-based move.