Demo mode and photos

I have two problems- first off, I am more apt to be self sufficent. I would rather search for issues than ask. That being said, I have two problems are that are proving difficult (for me) to search for. Got an iPhone 4. This is my 4th iPhone; I've had all the generations. I am a professional photographer so I need access to my photos. The 360 pictures I had on my old phone did sync over from back up. When I open the photos aps, I see the pictures as a small thumbnail. When I tap on it, it is just a black screen. If I try and MMS or email it, it is just blank. This is not accpetable in any way for me. Thoughts on what to do here?

Second and just as confusing- I do not know how to descibe this, hence why it's hard to search for. My phone goes into a screen saver mode, like a phone demo mode. It'll play a video about diffrent aps you can get. I don't know what triggers this or why it turns on. Search for 'screen saver' and 'demo mode' are not helping me.

Thank you for reading and thank you for your help!