IMO trying to use personal training for a minutes-old new guy account is not the right tool for the job.
That early, the explanation needs to be mostly automated, and instant. Personal trainers being instantly available 24/7 might be possible, but it's inefficient AF.
IMO it should go something like guy logs in, goes through automated "What button/axis do you want to use for this?" and walk them through to the point they've got something along the lines of at least up/down, left/right, start engine, shoot gun, raise gear, views, rudimentary clipboard usage and how to use text. If they mess it up, there should be an option to go through it again at any point.
Help channel needs to be on by default, the new guy needs to be directed to it, and the mods need to police it for people being aholes on it.
Wiley.