The theory of navigation is available in books, sailing club courses and online. There is, however, no substitute for doing it offshore. With a knowledgable someone who has a kindly spirit looking over your shoulder, you will learn more about practical navigation, both inshore and offshore, in a weekend than you will in a classroom for a month.
The best teacher is your own logic, for nav is logical and relatively simple when you have the tools in your hand.
"if at first you don't succeed....Redefine success"!