Have a demo session. You're going to want to check how your characters work plain (make sure each person has control of their token), figure out how y'all want to do health, gm vs public rolls, make sure dynamic lighting works, establish a base understanding for affliction token markers. I'd encourage them to use the character sheets, it really makes a difference in ease of play, and try to get them to stick to the online dice. I've found some people who get mildly upset that online dice "don't work".

Run a oneshot to hammer it all out. The learning curve was minimal for seasoned players, and new players had the benefit of being told "this is the directory we use, so please look up things you don't know like dazed!"