How to delete AVAST from my MacBook Pro

I suggest starting with what Avast support offers for removing their apps. I did a quick check on the Internet and came across this article: Uninstalling Avast Security from Mac - Avast

From Avast support: https://support.avast.com/en-us/article/Uninstall-Mac-Security/

If I recall correctly, About Avast has an uninstall option.