Trial and Error

Some modules do not actually need you to do anything, and they just do what they do behind the scenes. Those modules, however, probably have no configurable options, or that serve only as those upon which other modules are dependent upon.

More commonly, a module you are concerned about is something that you can adjust permissions and options for. Some projects are easy to use, which is to say, their use is 'intuitive', and it will be relatively clear to you what you can adjust, and what you need to do to accomplish whatever it is that you may want to do.