Prerequisites for openCV
OpenCV has a module to detect faces, eyes etc. With pretrained models you may also be able to detect cars.
https://www.pyimagesearch.com/2018/11/12/yolo-object-detection-with-opencv/

There are many good tutorials online. Just have a look. 

So if you are happy with this, you don‘t need to know much about data science. However, if you want to go a step further and train your own models, you will need to look into e.g. Keras (with pretrained models).
https://keras.rstudio.com/articles/applications.html

My view is that OpenCV is a cool tool and you can do a lot with it. However, off-the-shelf applications have their limitations (of course).