MFlann41,
Recall the rules that you've been taught and have been diving by so far? Keep following them. Pay attention to all of the briefings (details), ASK QUESTIONS if you're unsure. There may be someone else that has the same question. This helps eliminate confusion and keeps the dive safe and on track.
Set up your gear, double check your gear and do a buddy check that includes hand signals...before entering the water. Don't assume everyone uses the same signals as you. Most incidents that happen in the water, could have been prevented before entering the water.
Slow down...take it easy...this will help you relax and settle into your dive. Making for a more enjoyable experience. By slowing down you will also improve your air consumption. No one is going to see the enitire ocean in a single dive, it's not a race. You will see more cool stuff if you slow down,than if you race through the dive. Check your air and depth guages frequently.
Be aware of your surroundings. Don't get sucked into what is only ahead of you. Look up, down and side to side, look into the distance.
Pay attention to your buddy, ask if him/her if they are "OK?' occassionally throughout the dive. If you see something interesting that your buddy might be over looking, point it out to them, share your experience.
If you're a novice diver I would plan to dive to 50' with a contingency of 60'.
Know your physical and mental limitations. If it makes you uncomfortable, don't do it. Meaning if something just doesn't feel or seem right...don't do it. If there is a stong current and you have no experience with currents, I wouldn't place myself or anyone else in that situation.
Most likely, you're going to have a blast because everything is going to be OK. When you finish you're going to want to do it again and you will be proud and thinking about the dive for a week afterwards. "That was awesome! I can't wait to do it again."
We expect a recap of your trip. Have FUN and be SAFE.