I think candy should be an easy thing to get. Maybe everybody starts with 20 candy that they can't use but they give out to their friends. and some buildings on the map should have NPC's that give you a few candy. But I think the more rare items should be given out through a few different halloween quests.
side note: why doesn't classic give you a list of quests that you can do? like in the menu. including the daily ones that say whether or not you've done it yet today?