The words “anything and everything” is an English idiomatic phrase meaning more the the sum of “anything” and “everything” as individual words.
A lot of people go up the wrong path by analysing “anything” and “everything” separately.
As individual words, of course “anything” is different from “everything.”
“Anything” means any one thing. “Everything” means all things.
But the phrase “anything and everything” doesn’t mean any one thing and all things together. It means whatever is available to and whatever that can be given or obtained by that person or situation.
A sentence such as “I will eat anything and everything” effectively means I will eat whatever is available to me and whatever is served to me.
From: https://www.quora.com/Is-the-phrase-anything-and-everything-redundant