Welcome to the Wonderful Underwater World!!! I am 67 and a PADI Master Instructor (MI-29030 now retired). I think I understand how you feel, and I’m excited for you. Two things I would recommend: first, see your doctor every year and pay close attention to your cardiovascular system. You can improve your breathing capacity and therefore your ACR (air consumption rate - the rate you use up your air) by a simple excise whenever you’re sitting in front of the TV (or whatever); breathe in deeply - from the diaphragm not simple making your lungs larger - slowly for 4 counts. Hold your breath for 4 counts, then exhale slowly for 4 counts, and than count your 4 counts before you slowly breathe in again slowly. The trick here is SLOWLY. You might feel light-headed. Stop and breathe normally until you feel normal. Practice this and over time you will be able to increase the count to 6, 8, maybe even 16 or more. By teaching your cardiovascular system to use all the air (O2 actually) you breathe in (instead of the 10-15% which is normal) you can dive longer and - I’ve found - more serenely. BUT NEVER NEVER NEVER HOLD YOUR BREATH UNDERWATER! Just breathe slowly and always have your airway open. That will be hard the first couple times you get wet because of the “thrill” factor, and that’s wonderful. Just be aware of your breathing rate and try and slow it down a little. Secondly: those stupid tanks don’t get any lighter. In Oklahoma you’ll be diving a lot from the shore and will have to walk with your tank and weights a short way to enter the water. A little weight training at home every morning will help. Do the 5 pound curls with each arm and then slowly hold the weight over your head with both hands and lower them behind your back (if your Doc says that’s OK) and do some behind the back lifts - again do not strain and do it slowly. If you go to a GYM (I use my local YMCA) all the better. Keep in shape - I’m not telling you anything you do not already know. Just use common sense and be in the best shape you can be and you’ll enjoy years of diving. Welcome aboard!