Mystery Garden allows trainers to discard one darkness energy to draw cards equal to the amount on the bench, which is a great way to get the cards needed quickly
Many game stores are known to buy boxed bulk for a certain amount per 1,000 cards, and you could even try to sell a huge collection of commons as a lot on somewhere like Facebook Marketplace
As I explained last week, one of the major mechanics in the set was "committing crimes" (defined as any spell or ability that targets an opponent or their spells, permanents, or cards in the graveyard)
These will speed up gameplay and stop mistakes
Both are quite aggressive: Gwen deals damage for each attacking creature you have while Miles buffs up your whole board
Essentially, this means if a creature has haste, you can attack with it the turn it enters the battlefield