Can I pick up old pre-Black & White style Trainers, Supporters, or Stadiums with Lillipup's "Pickup" attack?
You can get pre-Black & White "Trainer" cards, but not "Supporter" nor "Stadium" cards.
Pickup




x2
PickupPut 2 Item cards from your discard pile into your hand.


DigFlip a coin. If heads, prevent all effects of attacks, including damage, done to this Pokémon during your opponent's next turn.
Can I pick up old pre-Black & White style Trainers, Supporters, or Stadiums with Lillipup's "Pickup" attack?
You can get pre-Black & White "Trainer" cards, but not "Supporter" nor "Stadium" cards.
On my opponent's last turn, they flipped heads for Diglett's "Dig" attack. If I use Blissey V's "Blissful Blast" attack on my turn, would I be able to attach Energy cards from my discard pile?
No. Since Blissful Blast did no damage due to Dig, you cannot get any Energy cards from the discard pile with Blissful Blast.