Basically, pushing and pulling are ways to raise or lower contrast, respectively. But instead of doing it when printing, with filters or chemistry, you do it on the film before you even print. This makes it easier to get the print you envision.
However, if you are controlling all of your own lighting, you already have the best tool for contrast control that is possible. You don't really need to push or pull. They are more for dealing with uncontrolled lighting that doesn't give you the contrast (or sometimes the exposure) that you want.
At any rate, the first step in learning what to do with pushing or pulling is to become completely solid with normal exposure and development. Learn how to properly expose and develop your film, and learn how this renders scenes of different contrasts. IMO, if you are just starting, pick a film or two and a single run-of-the-mill developer, and stick with normal exposure and development until you are able to accurately predict what any given scene will give you on the negative, and thus on the print. Only by understanding the ins and outs and limitations of a normally exposed and processed film will you really understand why you would push or pull.