You mean besides being a subscriber to BOATING? (LOL)
Here's my take. First, take a course with either the US Power Squadrons or the United States Coast Guard Auxiliary. These are given all over the country, usually an evening a week for 8 weeks at thelocal high school so something and are basically free--there are a few bucks to layout for materials. You can google both, enter your zip code and course date and places will appear.
Second, get out and practice. Buy, borrow or rent a boat and approach it slowly. Pick one task, say docking or anchoring ,and work on that for a day. You'll find that taking it easy, going slow and your skill set will ramp up quickly.
Third, boat with friends who are boaters or join a yacht club, cruising club or fishing club if none of your friends boat.
Boating has been a lifetime of accomplishment and unending pleasure for me. May it be for you as well.