Plan your dive, then dive according to the plan! Leave some wiggle room in your dive plan too.
Leave only bubbles, take only pictures, and spend only time.
There's no such thing as "one size fits all," and no "this brand is best." What's best is what's best for you. So rent stuff like masks and BC's and regulators and fins, trying out different makes and models and then choose what's best for you before you spend money on gear. They don't all fit the same on every diver.
Try the low-volume masks (they fit close to your face, no side "windows" (they make me dizzy!) or other fancy stuff. Believe me, diving in a current is a pain with those big fancy masks.
The "lazy" diver is the best diver. In a current, do what you see the fish doing! Hug the reef or the bottom to stay out of the current and minimize turbulence. Make it easy for yourself!
Try reef dives, float dives, wreck dives, night dives! They all rock in their own wonderful way.
I always swim the anchor down and tie it off to the reef on reef dives. That's my backyard down there, and people who drag the anchor leave damage that looks like tire tracks on the reef where the flukes of the anchor have chewed up the reef. Some of the most popular dive spots offer buoys for boats to tie up to. They're anchored on the bottom very securely and are there to prevent the kind of damage I described caused by dragging anchor on the reefs.
It's the most awesome fun! You will absolutely love it. Even more fun when the wonder and beauty are shared with others!
NAUI-certified in Palm Beach, Florida