How can I find out the ISP passsword that was given to me , I presume when this set up was first established, I have no recollection of being given one.
It can be an all in one device yes.
But typically your modem plugs into the wall / or phone line. And the router is the second device that plugs into the modem. (router) is what provides the wireless signal. When you look at the bottom the sticker will say "wireless or security key".