I have had a client after an employee collapsed and had to be rushed to the hospital. He suddenly found himself this officer and having to show that he knew and had done things.
If so, a free first aid course like this one here might help. It is informative and is certainly better than nothing.
It took me less than an hour, and that was part-time, as I was doing much in the meantime.
Pick someone in the shop. Then have them do the course, so you do have someone that knows some first-aid then make them your medical officer. As a bonus, they can always add it to their resume as a qualification.