The modern document library in SharePoint is still a work in progress. Folks still tell me at times that they flip between the classic and modern views to get the best of both. Over time, things will definitely stabilize and we'll have just one view to work with. For now though, it's best to be familiar with both.
Our product team here at VisualSP created an annotated image to provide a quick tour of the modern document library. I think a graphic like this is beneficial to the end user struggling to understand the new components of the modern document library.
Feel free to use it as needed if it helps your users.