We use quite as an adverb, to describe something to a certain degree, or to the greatest extent.It is also used to describe something exceptional or remarkable, and also to express actuality.
Examples:
1 It was quite a sudden change for Elliot to move out of his parents' house.
2.Sasha's victory at the junior Olympics was quite something!
Quiet
As an adjective, quiet is used to describe little or no noise, or something that is calm and untroubled.As a noun, we use it to signify the quality or condition of being quiet.
Examples:
1.A menacing quiet fills the empty streets.(Time)
2.Brandon likes to spend his afternoons near a quiet lake.
Act Up
Examples:
1.The washing machine is acting up again. I can't get it to work!
2. Melisa always acts up when she doesn't get what she wants.