Welcome to the forums!
Sorry for the trouble.
There's only one app that I know of for that. It requires that your phone be rooted and it only _might_ work.
The problem you have comes from Google and your phone maker, carrier not involved.
You have an extended storage phone, so you have a slice of your built-in storage masquerading as an sd card. That's why apps work with it, the Android way has always been to have an sd card available. If you also have an actual sd card, that's the only one you can access as usb storage, as you've discovered.
The Android way, per Google, of dealing with your "internal" sd card is to only access it using the media transport protocol, MTP, a Microsoft standard that allows two things to connect at once, your phone and a pc, unlike usb storage.
And because two things connect at once, control gets messy and so does running separate tools.
I'm in the same boat with my extended storage phone, but it's a different model, so I can only suggest things in general terms.
When you connect, you ought to have another option, mine is called media sync, but I know Samsung has similar. With that, and a later version of Windows, your internal user storage will appear in your pc file explorer. Not sure, but you may be able to find Windows undelete tools that can manage it at that point, but they have to work with MTP, that's your search keyword.
Or, visit our root subforum here, root your phone following the guides posted there, and give that app a try. There's no guarantees on that, sorry.
And the more you use your storage, the lower your odds of recovery.
This won't help now, but maybe consider Dropbox to automatically sync your photos to their cloud and from there to your pc.
Sorry I couldn't be more helpful.
PS - don't sweat being new, we all were at some point here.