How to "fake" my way through a Catholic M...?

Just relax. People do different things at a Catholic m. Since the days of VATICAN II, many of the traditional requirement have been removed, yet many people still do some of them, such as genuflecting before entering the pews. Nobody will really care what you do, unless you do something really different, like start blowing on a kazoo!! Follow along with the m with a MISSLE that will be in the pew. It's not that difficult to blend in. And even if you don't, just explain it's your first time, and most people will be happy to help you along. Enjoy the experience.