Hello we hired a marketing assistant and one of her jobs is to maintain our shopify store by cleaning up unused tabs, moving products around, redesigning the layout - how the website functions (not so much the theme). Are there courses she can take to learn how to do this and more?
For a big platform like shopify the academy is only starting structure for basics, the overall learning ecosystem is a diaspora of tuts you'll find online through searching.
Shopify's a big system with it's subsystems also having a lot going on (i.e. themes) with frequent updates, so keep in mind "courses" often lag behind in different ways depending on what you find online check the creation dates of tutorials.
If your working with a shopify-partner get them on a retainer to answer questions.
And ask them to help setup a staging store for the staff to have a safe development environment to work in while learning the systems; optionally syncing data from production to the staging environment.
DO NOT have untrained staff playing with a live theme.
If the store is on a shopify Plus plan setup a sandbox store.