Freemasonry is not a secret society... after all, you're reading this page aren't you? Masonic halls normally advertise their identity above the door and can always be found in the phone book. Freemasons themselves are encouraged to freely acknowledge their membership (although they are forbidden to try to use membership to further their business activities).
Freemasonry is a private, members only, organisation. Like any such organisation its meetings take place in private. Membership is open to any man over the age of 21 who believes in The Great Architect Of The Universe.
Masons are taught "secrets." These are not sinister but can be analogised to a historical version of being given the combination to the lock on the door of the lodge, much as members of any other organisation might have the combination for their club house. Just as the club-house combination cannot help away from the club, so the "secrets" of Freemasonry serve no purpose outside the confines of the Lodge.
These days, the "secrets" of Freemasonry can be obtained from many books in the library but you will never hear them from a Mason. There is one good reason for this; we have all promised not to reveal them, and as men of our word we will not.