Howdy Meg,
Any mention of Bophomet with the Templars inevitably leads to side-discussions, alas.
Your medallion was probably set out for sale as it has O.T.O asociations and also some connection with Satanists, who find the demon sympatico with their interests. Bob's reply can give you other associations that you may find more aligned with your own beliefs should OTO/Satanism not be true of your background. My own suggestion is to be mindful of the medallion, place it in a spot where you can see it every day, offer it some form of worship such as incense, and see how Baphomet decides to contact you. Contact is likely to take the form of a string of 'coincidences' such as cutting a tarot deck and getting the "Devil" card (which is supposed to be "Baphomet") or something like that. Keep a listing of these events in a journal with date and time and, once a month or so, review them for any alignments such as phase of the moon or particular day/hour and see if they give you any insights. Otherwise wear it, see who reacts differently to you, and enjoy your day with your spiffy new jewelry.
Blasted Beets,
--M