Some of the better selections to start with for classical music are ballets and dances. If you have a classical music radio station, you will get to hear a variety of classical music. Another area is the musicals. Some CDs are the popular selections from various musicals rather than the entire musical score of one production. There are also CDs that are the classical music used in cartoons or movies.
Movie soundtracks are also very popular.
The current box office hits may be overused but the older movies can be a good choice. If you do buy any CDs to find music, try to locate a store that will let you listen to a CD first. If not, try to find a store that will let you return, usually for exchange only, a CD that has been played. The larger music stores will have a person in the classical music department that may be able to help you as well.