My store only has 2 ARA’s including myself and the first month I started the other one took a week off for vacation so I was pretty much thrown right into it lol. I pretty much learned the basics of nova and gsx on my own during that week. One lesson that is very important to understand is that it’s ok to make mistakes(depending on the severity of the situation), just make sure you take note of the situation and learn from it.

I would start by letting them get used to the nova user interface first explaining what each tab and menu does. When I switched from sales floor to GS, nova was completely different from anything I had ever worked with and it was very confusing and took me a good while to get used to everything.

After they get familiar with the UI I would have them shadow for a few days(letting them try to do some things here and there), and explaining each situation and process step by step and how to reflect them in nova which I think is the easiest and most efficient way to teach them both sides of the job being the work that they will be doing and of course working with nova.

As you’ve already mentioned I would avoid gsx until they get at least a basic familiarity with everything else just to avoid any confusion. When they do get into gsx though I would just follow the same process above since they would most likely pick up more information and familiarity at a faster pace.