When I purchased my first drysuit I got sat down in the shop in front of a video that went over the basics of drysuit diving. I then went to the pool for about an hour with one of the shop DM's who had me do a few basic exercises. They told me to enjoy the suit and sent me on my way. Ironically, over the 12 years I was a NAUI instructor I taught the drysuit specialty several times, and issued a bunch of drysuit c-cards ... but to this day I have never owned one, despite doing more than 3,000 dives in a drysuit.
The class I taught began with the NAUI video ... which was dated even when I taught the class, and has since been discontinued. But it did provide a good overview of the basics, and established a basis for conversation about the different types of suits and options available, as well as the inevitable suit-vs-bcd for buoyancy control discussion. After the video we would go over basic maintenance of seals and zippers. I'd show them how to remove and replace the valves. We'd talk about proper fit, undergarment selection, different choices for things like socks, gloves and hood. I'd show them a few different options for zipper and seal lubricants, and talk about the pros and cons of each.
The in-water portion of my class didn't involve pool work, as I lived and taught just a few minutes from a pretty nice dive site. We'd go down there for a couple of dives. The first dive was shallow ... 20 feet or less. We'd do the basic safety drills ... inflator hose removal, how to manage air in your feet, tuck and roll maneuver for recovering from a feet up situation, and spend quite a bit of time practicing buoyancy control and trim management. Second dive was more of a fun dive, just to get some practice managing the suit while changing depths. We'd typically keep that one to 60 feet or less, but with a lot of depth changes to give the student some practice adding and venting suit air.
The class typically took a day, and I charged $150 for it, which included student materials and c-card.
FWIW - I always told students before selling them a class that they could learn all this stuff without formal training, and that the only real thing a c-card got them was the ability to rent a suit ... no self-respecting dive shop would rent them one unless they could show proof of training.
... Bob (Grateful Diver)