It is vast, you are right. But it is not all a sacred tome. There are a lot of different styles of composition, some which you, depending on tastes, will simply not like, just like any other music.

The mainstays of popular classical music, Bach, Mozart, and Beethoven all practically defined the 3 main "periods" of the genre; Baroque, Classical, and Romantic respectively (though Beethoven is often considered as somewhat of a bridge between late classical and romantic, details..). Thus each of these periods has a unique character and sound, which is as distinct as different genres of modern music, despite mostly using the same instruments.

It is unfortunate that all that variety has been slapped the label of "classical", and somewhat ironic, considering the Classical period of classical music was seen at the time as a reaction to the "overly complex, aristocratic", style of baroque. It was the pop music of its day, now of course regarded as somewhat elitist.

Anyways, I'm somewhat of the Glenn Gould opinion that Mozart is mostly trash (though his keyboard concertos are pure gold). I suppose the wannabe elitist in me gravitates towards baroque, it's intricacy, specifically counterpoint. If the idea of multiple independent melodies playing at the same time, transforming and complementing each other like some kind of musical puzzle fascinates you, as it does me, then I'd suggest binging on some sweet J.S. Bach. You've surely heard BWV 565 at least once every Halloween, and a few of the Brandenburg's. I'd suggest listening to some of his keyboard works, which are easier to digest and comprehend the contrapuntal melodies than some of the orchestral works. Two Part Inventions/Sinofas, WTC I && II, Goldberg variations, etc. Youtube will provide. A lot of these songs are very energetic, with a steady driving beat that you could dance to if you didn't care about getting made fun of by your friends. There's an almost classic VGM style to some of it (or maybe it's the other way around..).

But this is all just like, my opinion, man. Point is to find a song that you like, find who wrote it, and then find more from that same person. Then expand to their contemporaries. If you hear something that does not appeal to you, even if it is a purported super classic, move on. The popular classical music that literally every body nowadays has heard, tend to be shallow and trite examples of what the composer produced in their time (Beethoven was reportedly quite peeved even then that so many obsessed over the Moonlight Sonata. "Surely I have written better things"). Dig beyond the stereotypes and you will find some real gems.

Classical music is a literal treasure trove for those who enjoy instrumental music, and even mad guitar solos (piano was the guitar of the day. The level histrionics, hype, and raw skill demonstration that can be achieved on the piano keyboard can be truly mind blowing. I've always been a big fan of guitar solo legends, David Gilmour, SRV, Eddy Van Halen....but damn. (Check out the cadenza in Brandenburg 5 [1], or almost any Liszt piano solo [2])

[1] https://youtu.be/vMSwVf_69Hc?t=81
[2] https://youtu.be/2X_hOY6tEvM
[for fun] https://youtu.be/qB76jxBq_gQ