Whether those creature were yours that met their doom through sacrifice, or your opponents' that ate destroy spells or sweepers, well, the Cult of Rakdos isn't too picky
At first blush it might seem that all your morph creatures would get blown away by a single Bile Blight, but heres the relevant part of the comprehensive rules about morph: 702.35b
Start there, claim the first-pack safety net, and keep this guide bookmarked for when you are ready to branch into the marketplaces, graders, and vintage hunts the other names do best
Of course using artifacts or enchantments that can dodge board wipes and other removal can be great as well
Whenever you cast a creature, you draw a card
Finally, starter decks come with a single booster pack of 12 random cards