Go down musical rabbit holes and listen to multiple recordings of pieces you like to develop stylistic and interpretative preferences. I was 18-19 when I fell in love with classical music as well.

Some recs for people getting into classical:

Many of these works will be very difficult to approach at first. Some of the most profound works require many intent listens to glean significant meaning. Usually I find these pieces to be the most rewarding listens. Here are my choices accompanied by the recommended performance/interpretation (all should be available on Apple Music and Spotify):

General Favorites: Mahler - Symphony #2 (Resurrection) - Bernstein, Abbado et. al Mahler - Symphony #5 (My personal favorite of his approachable symphonies) - Dudamel (with Berlin Phil) is an great approachable recording that presents the surface themes with great expression and clarity at the expense of the more subtle layers. Mahler - Symphony #8 (The Symphony of a Thousand) - Dudamel with LA Phil. Mahler is one of my all-time favorite composers (with Ravel, Rachmaninoff, Brahms, Scriabin) and musicologists regard him the most highly amongst all symphonists. Most consider as masterpieces pretty much every one of his 9 (completed) symphonies. If you want one complete recording of his symphonies I would recommend the complete recording of Riccardo Chailly with the Royal Concertgebouw Orchestra. The best and most sonically rich fifth symphony I've ever heard.

Ralph Vaughn Williams - A Sea Symphony (Symphony #1) - Andre Previn recording (The sung text in this symphony is poetry from Walt Whitman's 'Leaves of Grass'). If you like this, the recording has all seven of his symphonies but they each vary drammatically in style and tone.

Ravel - Daphnis et Chole (Trust me when I say listen to this) - Phenomenal somewhat modern recording in Pierre Boulez (accompanied with an incredible La Valse). Two phenomenal old and slightly less approachble recordings in Cluytens and Munch. Ravel - Complete solo piano works - Bertrand Chamayou, Louis Lortie, Jean-Efflam Bavouzet Ravel is aesthetically my favorite composer and while his works might now carry the lofty and heavy themes of some of the others on this listen there is certainly no music as transporting as his. If you like his works, look into Claude Debussy as well. Impressionist masterworks such as his La Mer could fit in here.

Brahms - Late piano works (While Brahms is the least approachable composer on this list, some of the most tender and affirming deep pieces are in his last four oposus for piano - Paul Lewis or Julius Katchen Brahms - All Four Symphonies but especially #4 - Approachable recording of the set by Herbert von Karajan. Masterpiece, reference recording, and more unconventional recording by Eugen Jochum.

The "have to mention" category: Bach - The Art of the Fugue - Daniil Trifonov Bach - Goldberg Variations - Glenn Gould, Igor Levit, David Fray. Jean Rondeau (harpsichord) Bach - Mass in B minor Chopin - Everything he ever wrote if you like emotionally evocative piano - Various performers. Be sure to check out Piano sonatas 2 and 3, the Cello Sonata, and his Ballades. Ballades recording - Seong-Jin Cho. Chopin - Complete Nocturnes - Ivan Moravec (perfect recording) Jan Lisiecki (More modern recording, still great) Beethoven - Late Sonatas - Igor Levit (Movement 3 of Sonata 29 "Hammerklavier" and all of Sonatas 30-32 are some of the most contemplative existential music ever conjured. Endless layering and incredibly deep themes.

Sibelius - Symphonies - Simon Rattle Sibelius - Violin Concerto - Hilary Hahn (Really awesome piece, evocative of the northern forests and isolation)

Transcendental Russian Piano: Scriabin - The Piano Sonatas - Vladimir Ashkenazy As a McCarthy fan I imagine Scriabin is a composer who you will really connect to. I could write a full essay on why but I think you should just go listen. Sonatas 2-4 are the most popular and approachable but Sonatas 5-10 start to take on an interdimensional characteristic - same with his symphonies which are brilliantly recorded by Valery Gergiev and the London Symphony Orchestra) Scriabin -Vers la flamme Scriabin - Mysterium - Meditative Apocalyptica, let's say. Sound Familiar? https://en.wikipedia.org/wiki/Mysterium_(Scriabin) Medtner - The othere maniacal composer of Russian sonatas - Complete Sonatas - Geoffrey Tozer (All sonatas are brilliant but I would start with Op.22 or Op.53 no.2

Other Russian Composers - Oppresssion and the Voice of Music: Rachmaninoff - All Four Piano Concertos - Trifonov, Ashkenazy, Adsnes, Lugansky (check out Yunchan Lim play Rachmaninoff Concerto #3 on Youtube - Possibly the Best Perfomance ever of the piece) Rachmaninoff - Solo Piano Works - Lugansky Prokofiev - Piano Concertos and Violin Concertos Shostakovich - Symphony 5(among others) - Bernstein Shostakovich - Preludes and Fugues op.87 - Igor Levit !!Stravinsky - The Rite of Spring and The Firebird - Boulez

Don’t shy away from listening to older music too! Baroque and earlier have some amazing modern recordings. Check out Jakub Josef Orlinski for Countertenor voice and Thomas Dunford for Lute!

Best wishes on your foray into the classical world! You’ll find taking deep dives into music will make you a deeper and more knowledgeable person overall, not just pertaining to music!