Initialize Camera with a dynamic scene

I have a scene that keep changing and thus the location of the camera and viewport must keep changing. Before asking really stupid questions, I am asking for links needed in order to understand the positioning of the camera, frustum, and viewports without having to learn everything related to 3d graphics

If it’s about positioning, take a look there: https://wiki.jmonkeyengine.org/legacy/doku.php/jme3:scenegraph_for_dummies