HDryder05

First I will apologize up front because I'm rather out of my element on this so any help is greatly appreciated. I recently purchased a large rental property that has a CCTV system installed on it (on the exterior and common hallways) but I have no idea whether it works or not. All the cables from each camera go into the basement to a tan box. My question is simply how do I go about finding if the system is operable and how can I use it. Where should I start? Thank you in advance for any help on this subject.