Welcome!
Lots has changed in 30 years:
Digital sources has come a long way. CD's are all but dead - CD quality streaming is all the rage. Higher resolution formats are everywhere in the gear and reissues, but not so much in new music. Most of us have ripped our CD's or saved them to streaming sites as favorites. The advent of streaming and advances in all things computer related has greatly lowered costs and made sourcing very slick. For instance I use an all-in-one streamer/DAC/preamp/power amp that is friendly, yet flexible and compact.
Another digital advance is Class D power amps. Highly efficient, many are small/light, and less expensive. Only old timers or those wanting the very best in big iron still cling to class A or A/B amps.
Vinyl hasn't changed much. And tape is all but dead. But there has been a resurgence in tube gear. And a great deal of interest in cables of all kinds.
A couple of developments have come about in speaker design. Lots of interest around here in open baffles (dipoles using dynamic drivers mounted to a simple panel). Active monitors (like the studio guys use) has gained traction. Active design uses sophisticated low voltage crossovers to feed one channel of amplification per driver for greatly improved technology and sound at lower prices. Another new concept is controlled directivity which helps take the room out of the equation. In general the sound of speakers have gotten leaner and tighter, what we used to call the European/Scandinavian sound. To counter that, lots more interest in subwoofers.
Finally, the room has gotten some attention. Proper room size/shape, acoustic treatment, speaker/listener setup, use of multiple subwoofers, and room correction (formerly EQ, now computer based) have all entered into the discussion.
Of course most of the bricks and mortar shops have closed. Have fun getting up to speed in this internet based world.
