I am obsessed with classical music, how do I get started and understand a piece of music?

Western classical music is a system. And you are now in a stage where the blind men are trying to figure out the elephant. I touched something, but I don’t know where exactly it is. What I listened to were some isolated pieces of music, without connecting them to a complete work, nor to the entire background of Western classical music. First of all, you can start from the scope that you are familiar with now and work from point to surface. For example, if you listen to Tchaikovsky's Waltz of the Flowers, do you know which piece it is from? It is a selection from the dance drama "The Nutcracker", so you might as well listen to other songs from "The Nutcracker" and learn about the plot of the play. You will hear many familiar melodies in it. Now that you have listened to "The Nutcracker", can you also try Lao Chai's other famous dance drama "Swan Lake"? You can also expand on other songs you are already familiar with. In addition, there are many terms that need to be understood. Just start with the title of the song. Waltz, serenade, nocturne, sonata, symphony, concerto, etc., you can check the information online, which is very convenient. Introducing some representative and relatively popular songs to you according to the style of the times. Pachelbel, Canon, Pachelbel Canon, Canon means singing in turn. In this piece, the violins are divided into three groups. The first group appears first, the second group appears four bars later, and plays the same tune as the first group to catch up with the first group. The third group appears four bars later than the second group. Show up and play the same tune to catch up to the second group. If you listen carefully, each melody will cycle between the three parts three times, and will be superimposed with other melodies that are going on at the same time. Vivaldi, Four Seasons, Xiami Music, this series consists of four pieces, spring, summer, autumn and winter, each with three movements, so the series has twelve pieces. The genre is violin concerto.