POP ROCK Eddie Money: ''Where's the Party?'' (Columbia FC 38862) - Ex-cop Eddie Money loves rock-and-roll. He loves to sing about girls. And Eddie loves life in the fast lane. His new album - as have his others - conveys that message to us in his freewheeling rock style. ''Where's the Party?'' is an average album for the average 16-year-old. The themes are simple, the music (for the most part) fast, and the singing adequate. Although Money has never excelled in the vocal area, he makes the most out of a limited range. The title track is a fun, fast song done in a '50s rock style. In sharp contrast is ''Backtrack,'' dealing with the fear of growing old. It offers some novel - for an Eddie Money song - guitar and piano instrumentals. Other songs of note on the record are ''Maybe Tomorrow,'' with its typical upbeat, driving rock beat and forceful, strong vocals, and ''Club Michelle'' - a mysterious adventure of a man's fruitless search for a nightclub where he fell in love. This song is a collage of dead-end streets and frustrating closed doors as we follow our knight in tarnished armor through the search.