I turned on auto-save and set it for 5 minutes. When I am working on an image, if I don't do a Save As or a Save, nothing gets saved (that I can find anyway). How do I verify that autosave is working and where do I find the updated file?
You are correct that if you do not do a first save, autosave will not initiate.
On windows you can find the folder here:
C:/Users/USERNAME/Appdata/Roaming/Adobe/Adobe Photoshop CC/AutoRecover
However, the files are tmp files and only way to read/recover is to let Photoshop initiate the restore after a crash.
This is not an auto backup feature where you can pull iterative versions from this folder.
Auto save is for file recovery in the event of a crash. If Photoshop crashes the autosaved file will open automatically, if Photoshop closes correctly , the autosaved file is deleted.
If your scratch disk is on your primary disk auto save is to C:/Users/YourUsername/AppData/Roaming/AdobePhotoshop[version]/AutoRecover
If your scratch disk is another drive then auto save is to the root directory on that drive
Jumping in here - I often have Photoshop show a message that files could not be recovered after a crash. Is there anything that can be done?
Just offhand, I'd say that sounds like a folder permissions issue in your user account. That's where all of this is.
A more remote possibility is that the files were corrupted before the crash.
And all that said, if you have crashes often, you may have bigger fish to fry. I'd concentrate on that. Most commonly crashes happen because the GPU is old/incompatible/underpowered, you have a buggy GPU driver - or perhaps most likely, you have a laptop with dual GPUs causing conflicts. Post Help > System Info and maybe we can narrow it down.