Can you use Audino's "Busybody" Ability if there is no damage and no Special Conditions on your Active Pokemon?
No, you cannot. You have to heal something in order to use Busybody.
Busybody




x2Busybody
Once during your turn (before your attack), if this Pokémon is in your hand, you may reveal it. If you do, heal 10 damage and remove a Special Condition from your Active Pokémon. Then, discard this Pokémon.

Hip BumpIf the Defending Pokémon tries to attack during your opponent's next turn, your opponent flips a coin. If tails, that attack does nothing.
Can you use Audino's "Busybody" Ability if there is no damage and no Special Conditions on your Active Pokemon?
No, you cannot. You have to heal something in order to use Busybody.