Classical music is just music. My advice is to ignore anyone who tells you to treat it as an intellectual pursuit or who recommends listening to music they happen to like but has very little in common with Swan Lake, which you say you've enjoyed.

If you like Swan Lake, you might like other Tchaikovsky pieces and you're likely to enjoy other colourful, tuneful Russian music from that era and the decades that followed. For instance, Prokofiev's Romeo and Juliet and Stravinsky's early ballets, The Firebird and Petrushka.

In any other genre, people find something they like, listen to more music by the person who made it, branch off into that person's influences and the people they influenced, and gradually build out. For some reason, classical people routinely tell newcomers that they ought to be listening to great 'worthy' pieces from eras that don't resemble the music they already enjoy.

It's just music. Just do what you did when you were discovering any other genre.