I have to add something here, as I think "skubakat's" post may alarm people unnecessarily. I think the main thing is to see whether the shop is registered with a recognised training agency, such as PADI. The individual taking you out may be a registered DM or instructor, but that's not the same thing. If the shop is registered then it's likely that everything else will follow. If you have any doubts, ask to see the following on the boat: first aid kit (should be comprehensive); oxygen unit (check it's full); communication equipment present and in reliable working order (in this area usually a cell phone, which must be charged and with credit, or may be a marine radio that should receive and transmit); anchor and chain/line; ladder; flares; navigation lights at night. There may be things I've forgotten. Such as the basic one that the boat is in good order, the engines work and there's plenty of fuel. In any case, most of this is required by law and under the operator's licence issued annually by a government agency.

There is only one recompression chamber, and that is in San Pedro. If the dive shop is affiliated that helps, but more important is that they know the chamber and how to contact/reach it. Very important here is that you, the diver, have proper dive insurance - the dive operator should be able to advise and help.

I have never (in several thousand dives) heard of anyone with properly fitted gear hitting their head on their tank valve on a back roll entry. It is by far the most common form of entry world-wide. I wouldn't call any entry technique "dangerous", though anything can be made dangerous, like back rolling with no air in your BC into very shallow water with rocks at the bottom. Ultimately there's no substitute for common sense.

Don't know what "evacuation procedure" means. We're talking here about small boats. I can't imagine when you would need to "evacuate" a small boat, but I can't believe you would be in any doubt as to what was needed and intended. One thing not mentioned that could have been is what the "diver recall" signal will be (how divers under the water are told they need to return to the boat immediately). That is very rarely required, but should be part of the normal dive briefing. In any case, as a student you have no need to know anything like this - your instructor will take care of you.

I don't know what "skubakat's" credentials are, but both Elbert and I have many years' experience, many dives, and have certified many students. We do know what we're talking about.

Allie gave good information. Diving is great fun, very safe when conducted sensibly, and very few people are barred from it for medical reasons. Try it and you'll love it!