SharePoint Server Subscription Edition AMA

Hello, my question may be a bit basic, I've been tasked to create training around how to use Sharepoint more effectively, and efficiently, as well as straight-up how to use it for the people who aren't using it. Do you have any good resources I can tap into to help develop the content for this training? I've done my fair share of searching Youtube and there are some great resources there but I was wondering more from the actual source. Thank you!