Garmin published new videos from their G3X pilot academy. One is an introduction into the G3X, and the second is regarding the autopilot.
G3X Pilot Academy: Introduction https://www.youtube.com/watch?v=m1ylNkG1x1A
G3X Pilot Academy: Autopilot https://www.youtube.com/watch?v=R-DDw6k-07M
Also, more information regarding other Garmin equipment, like the GTN and the G5 and more can be found on YouTube under https://fly.garmin.com/fly-garmin/training/
It is really worthwhile to have look at this outstanding material. The videos give a very good detailed overview of the possibilities with these state-of-the-art avionics.
The Flight Design Team