As others have noted, it's useful first to understand the setting and context for a given period or style of classical music. After you've read an overview or

As others have noted, it's useful first to understand the setting and context for a given period or style of classical music. After you've read an overview or few, pick representative pieces of each sub-genre, preferably ones you've already read about or which you already recognize, and start listening to them through a new lens. Then, pick a sub-genre you enjoy and dive deeper. Read a more pointed book or few and start listening more expansively to works by multiple composers. Ignore the performer and conductor/orchestra/symphony at this stage. Start appreciating the macro-level structures that make them what they are, and the internal nuance that makes them famous. If you find yourself particularly drawn to something, whether it's a genre, a time period, or a composer, dive deeper. At that point, you should start listening to multiple recordings of the same pieces and get a feel for the difference an arranger, conductor or performer can make (or if you want to become a true fanatic, an orchestra/symphony, venue, or recording equipment). If you get to this point, it becomes a passion just like any other, and you can start calling yourself something of an expert. :) (Source: play classical piano and am currently trying to pick up popular guitar to have something more accessible & casual.)