Talk to samsung warranty department. Walmart may not take it back as a return of unwanted phone, but it has a warranty. As this sounds like a hardware issue, I would contact both samsung and walmart technical support.
In your contacts, select a contact you want to add the photo to.
At the top of the screen there is an edit "button", press that.
Then where the photo should be there is a "+", press that and tell it what photo to use.
When you say cannot use phone. Can you please explain what exactly is the problem and what it shows when you turn it on, or is it turning or properly or not.
With issues like that, I would back up the device and do a factory reset. I attached a video that shows you step by step on how to do so. If you have questions, let me know. I’m happy to assist further over the phone at https://www.6ya.com/expert/christopher_d13aca62d29ed9ae