A person who sells suits is commonly referred to as a "tailor" if they also make or alter them, or as a "suit salesperson" or "clerk" if they primarily focus on selling. In some contexts, they may also be called a "haberdasher," particularly if they sell men's clothing and accessories.
A person who sells jewels is called a jeweler.
A haberdasher.
A glomber
jeweler
A florist.
clothier
The person who sells drink is known as sellsmen
An author is a person who writes and sells books.
baker
A bookie. Droll. You could call that person a bookseller or shopkeeper.
You call a person who sells flowers a (Florist)
A person who sells ship supplies is called a chandler
A tailor.
A person who sells jewels is called a jeweler.
fishmonger
A chandler.
A haberdasher.