i buy flowers from a florist and you buy shoes at a shoe store .....what differ en? both sentence....

In the first sentence the object 'a florist' is a person and in the second 'a shoe store' is a destination.

I buy flowers from a florist. Here, "florist" is a person who sells flowers. You buy shoes at a shoe store. Here, "shoe store" is a specific place, not a person where shoes are sold.