Did my first ever dive in Cuba seven years ago so it was some time ago, but i will tell you what it was like then.
If you have your own equipment take it with you the equipment we were given for our try dive was pretty poor.
Safety was not much of an issue either, we only had one reg, no buddy system was discussed or offered, we went down to 30m and in an overhead enviroment, they also tried to sell us as much beer as posible between dives.
But then having never dived before I thought this was pretty cool and a sport I could easily get into.
Having said all that though, the diving was pretty spectacular (well compared to stoney cove it is) the sea was hot(unsurprisingly we were not given wetsuits) and the Cubans were very friendly people.
We dived somewhere East of Havana but I can't remember where.
When we went tourists were mobbed by people begging, don't know what it is like now, we took chewing gum for the kids and little hotel soaps for the adults I know it looks like you are taking the p**s giving out soap but you make instant friends as they can't get perfumed soap we even had people coming up to us and showing us pictures of soap, this was seven or eight years ago so maybe it is a bit better for them now they still have the US sanctions but European tourism seams to be bringing money into the counrty.
Good luck with your diving.