Advice: Looking to add some type of network storage to my home network

I’m looking to add a network storage device of some kind to my wireless home network. I would like to be able to get all of my wife’s pictures that she has on 3 different computers to one central location.

Coupe of questions,

1. Are these easy to setup/install on the network?
2. Is there one that is more user friendly than the next?
3. Am I able to access the photos/videos anywhere I have an internet connection via and app of some kind?

Thanks in advance for any help anyone is able to provide,