I have looked a bit around for RocketChat trainings, workshops or the like for me and possibly one or two of my employees. The only thing I could find is this one: Running Your Own Chat Server with Rocket.Chat Training Course . Although, judging from their description I suspect that their traning may be doable (though maybe challenging) for me, but far too techical for the others.
We are now learning RocketChat by trying things and checking the docs. If we let aside some initial struggles, it has actually been going quite well. So I think that now or in the near future it would be a good moment to follow a training, if there is any to find.