It's a great time to be a new or struggling audiophile. Check out the Cheap and Cheerful circle, lots of inspiration for systems. It's never been easier to assemble a decent/good system.
Having a computer you're 1/4 of the way there already, just add DAC, integrated amp, and speakers. Here's some inexpensive system ideas:
Rather than spend $$$$ acquiring a library of music subscribe to Spotify for $10/month (less than CD quality so audiophiles will cringe) or Tidal (CD quality) for $20/month.
Learn what you want and what will work for you. If you don't have good opportunity to listen in-room where you live due to various domestic limitations, consider headphones for serious listening. Schiit is an American company that is quality, headphone, and value oriented.
With guidance you can score well in the used market, especially if you're handy inside components or can accept yesterday's technologies (like non-HDMI receivers that still perfectly serve stereo use).
For background listening I picked up a $99 Logitech UE Smart Radio (basically a super nice wireless alarm clock) for our living room. Very pleasant sound.
For $250 you can have a tiny desktop pair of Audioengine A2+ speakers and be done. The $850/pair KEF X300A is a bigger/better version. These are just two examples.
Powered or active speakers (most are small) with a combined DAC/preamp makes for a very cost effective route. Separating components allows more flexibility to upgrade or pick and choose (audiophiles love the hunt).
And always protect your hearing. My highest value component is OSHA approved hearing protection.
