.If you can find a good instructor, a buoyancy class is a good addition to your basic training. UW photography is a lot harder than most think and requires a lot of instinctive skill, your buoyancy control needs to be second nature and something you are doing without thinking about it. Task loading jumps a lot with a camera in your hand and buddy skills suffer. If you have a regular buddy, diving as a photographer and guide team is a good option, esp. in the early days. I know the desire to shoot UW photos but until you get your skills up, look around the group you are diving with and see if there is a good amateur photographer, most of the time they are happy to share their photos with you. You get much better pictures, get to observe them (hopefully they are a good example) and you might get in the shot as well.
Here is my test to see if you are ready.
Go to a dive spot where you can't hurt anything - a pool or sandy bottom quarry are perfect. Find a spot at least 6- 8 ft deep that has a vertical surface with something you can "focus" on at least 3 ft from the bottom or surface. This can be anything, a small rock, a paint mark, a piece of tape you put there, a spot you rubbed dirt off , anything. This becomes your photo subject.
Now move several feet away from the object, hold your hand out in front of you with your thumbs together and index fingers pointed up- the classic "director framing the shot" from old movies. Keeping your arms extended, ease up to your photo "subject" while keeping it in your hand framer, get within 6 inches of it, HOLD that position for at least 30 seconds ( you are now framing and focusing the shot) then the back away without using your hands. You must stay horizontal, not sink, rise or bump into anything. After you have backed away several feet, turn, swim away, repeat this several times. Have a buddy watch you to see if you sink, rise or kick anything while you are doing the test. If you can do this easily, you are ready to grab a camera. This is not easy.