The ordinary name for a person who sells bread and cakes is a "baker," since traditionally, the same person who baked the bread and cakes also sold them. In modern commerce, baked products might be sold by many sorts of sales persons or retailers.
The person who sells drink is known as sellsmen
An author is a person who writes and sells books.
baker
A person who sells books is commonly referred to as a bookseller or a book vendor.
You call a person who sells flowers a (Florist)
A person who sells ship supplies is called a chandler
A person who sells jewels is called a jeweler.
fishmonger
A chandler.
A butcher.
A haberdasher.