Greetings
I'm a lead developer at one of the outstanding software houses in Egypt. Working with open source tools. and on big projects.
My responsibilities include providing coaching and training for the rest of the teams on the tools we are using. which includes git. I actually prepared related training material about git for an internal session.
However, for a 3 days workshop, we can help attendees to try things to get hands on experience.
The basics should be covered in the first day,
Then collaboration, and more advanced topics should be covered in the next 1.5 days.
I'd highly consider leaving some space at the end to see what we can focus on more with trainees. and what will be useful for their business.
Regards