You need to learn the navigation rules, and what buoys and other aids to navigation mean. This page has some resources for you.
You need to learn about marine weather, so you can be safe and have fun. Know where to get forecast information and how to know what it means. Some resources for you.
One of the best ways to start boating, and do more of it, is to connect with other boaters in our area. Here's some tips for doing that.
If you take friends and family out boating, they're trusting you to keep them safe. Know how to do a float plan. You are also required to have certain safety equipment on board.