How to put camera following a npc while you controll your player?

Im gonna try be more specific:

I have this character that is a NPC:

And the i have this camera that I want it to be always on this side of the square (arena) like a typical camera in a football or basketball game:

What i want is to this camera to follow that NPC character without rotation, and i want this camera to be the main and starting camera.

Hope I was clear. If you could help i would be really greatfull