Is garlic used extensively in Creole and Cajan food?

Most definitely. Many recipes were handed down by the original French settlers expelled by the British from Acadia (New France, Nova Scotia now) in the late 1700's after the British defeated the French.

With no refrigeration, garlic was used as a food preservative, and to destroy germs, although they did not know about the benefits then.

Garlic is a major component in all Creole and Cajun spice mixes that can be bought - read the labels. In order of quantity, the first ingredient is the most predominant.

Answers is a Jungle

It is one of the hallmarks of Creole and Cajun food, yes.

It isn't a party w out garlic.

Yes. Along with Italian food.

It is used extensively in those foods, and in others.

Dune

Surely. It gives the right flavor.