How do I Access/manage Network from anywhere?

Hi I need to know how to manage and access a network from virtually anywhere. Our network consists of a mixture of Androids, an IMac, 5 laptops with different OS’s installed on each, and printers. I am able to get them all to communicate with each other while in the office but having difficulties outside of the office. I need to find out how I can access each device from anywhere in the world to do updates, changes, etc. How do I do that?