Thanks for responses guys. Been a little while since I checked back in. So, I ordered a 4 in 1 card reader from Amazon that has a slot for a lightning cable (charger), micro SD card, SD card, and USB port, thinking I may want to view some pics I've already transferred to USB flash drives.
Apparently my operating system on the iPhone 5c is too old (didn't keep up to date on updates) for this thing to work. The idea for using the 5c was to have something I could hopefully use as a card viewer, backup camera, and possibly import sound files to (not sure if this is possible) and not have it all on my other phone. Also, so I wouldn't be running down the battery on my other phone.
It does work with an iPhone 8, but you have to import the pics to the phone in order to view them as large pics and edit or delete. You can only view as thumbnails until you import, which are too small for much detail. Also, it puts the pics in your other photos by date (I do see an album called Last Import, which would only include those imported).
I see some of the other card reader options use an app to allow you to view large pics and edit or delete (I believe without importing to your phone). I'm wondering if there are any options that allow you to view large pics, edit/delete, without importing or using an app, other than a dedicated card viewer or digital camera.