what data structure to use?

[BashBedlam]

If it were me I'd use a class.

class Zip_Code_Entry :
	def __init__ (self, zip_code) :
		self.zip_code = zip_code
		self.amenities = {}

	def add_amenity (self, amenity: str) :
		if amenity in self.amenities :
			self.amenities [amenity] += 1
		else :
			self.amenities [amenity] = 1

	def show_amenities (self) :
		for key, value in self.amenities.items () :
			print (f'There are {value} {key} in {self.zip_code}.')

first_one = Zip_Code_Entry ('12345')
first_one.add_amenity ('Churches')
first_one.show_amenities ()