LOL
Nobody from outside SE Michigan (aka the tri-county Detroit area as it was called when I lived there) ever gets the party store meaning. Yes, a party store to me, is a place to pick up beer, wine, liquor, chips, cigarettes, and sometimes a few basic food items.
My mother (an immigrant, who's English was not the best) used to refer to our local party store as the "little store" when she sent me on a errand to pick up something.
I really miss Detroit some times.