Welcome!
Assuming you're thinking about in-room listening suggest starting with your intended listening room. It should not be small or squarish, but should be well insulated and hopefully dedicated to allow proper setup and possible use of treatments. Advise you to read Floyd Toole's "Sound Reproduction" 3rd edition as the consummate audiophile primer on how speakers/subwoofers behave in-room. IMO the room is the second most important "component" for in-room listening, next to speakers yet is the most neglected.
A mistake I see audiophiles often make is to enter the big game hunter mentality, where they want to fill their poor sounding space with way over matched eye candy trophies (lots of flashy looking gear with thick faceplates and expensive veneer). Floyd's book will direct you towards smaller speakers plus subs. Your main speakers therefore don't have to produced deep bass, they should go where mids/highs are best produced (away from walls), and the subs should go along walls/corners where they bass is best generated).
Speaker selection is a very individual decision, but they should fit the room (fill the space without overloading it or being too forward/recessed in presentation). Picking speakers can only be done by careful auditions. Take a wide selection of your favorite music and take notes to force you to really listen. Limit yourself to 3 or 4 speakers per day to avoid listener fatigue, but take your time with serious contenders. Think about the type of speaker too. Monopoles (front firing) are the typical and come in a variety of forms, dipoles (including open baffle) are popular around here, bipoles (speakers firing front and back) are another option, omnipole generally fire upwards, vertical arrays use a line of identical drivers, and single driver speakers are the coherence kings but have frequency range/power handing limitations.
Each speaker type has it's relative strengths and weaknesses. Monopoles produce smaller but highly defined imaging. Dipole/bipole/omnipoles produce a larger soundstage, with dipoles often being very dynamic. Vertical arrays eliminate floor/ceiling reflections and can handle relatively greater power levels. Another option, usually limited to monopoles is active design, where low voltage signals are sent to the speaker. Active speakers then use a more precise crossover to send the signal along to multiple single channel power amps, one per driver for enhanced coupling. Active monitors is what nearly all studio professionals use.
After selecting the speakers, find a power amp that serves the speakers well. Then it's on to picking your source or sources. Vinyl is the traditional option. It forces a hands on hobbyist approach, but albums are expensive and a crap shoot to find ones in good condition. Plus turntables/etc. can get expensive. Nowadays digital is almost exclusively done via internet, either downloads (for high resolution) or streaming for CD or lesser (non-audiophile) formats. Streaming is affordable, offers millions of selections, and very convenient.
Digital allows for integration of several components. For instance I have a combination streamer, DAC, preamp, and power amp that comes with it's own operating and room correction software. But you can also choose affordable/highly competent combination DAC/preamps. If budget is a concern check out the Cheap and Cheerful circle. Thanks to advances in digital technology there's never been a better time to invest in audio.
