Just to add (and to maybe repeat what a few have said), those who may want to start playing who never have.
Although ball golf and disc golf share some of the same rules and name, don't get caught up in the trap that you need to have a bunch of discs to play. Unlike ball golf, you dont need a bunch of different discs for different distances. There are many times when you want to throw a high speed driver 100 feet, and even more times when you want to throw a putter off the tee.
One could get away with a starter pack for a good while, will come with fairly light weight fairway driver, midrange and putter. If you play much you will quickly get a feeling of what might be missing from that and start filling in the gaps.
You will often see people carrying around 20+ discs (I would fall into this category myself) but really if you were to look at my bag and watch me play much you'd see I probably throw the same 4-5 discs the vast majority of the time.
What usually ends up happening is you want to have a duplicate or 2 of the main discs, and maybe extra putters for practicing (or more so, throwing putters vs putting putters) and then will also have some more niche discs such as a roller disc (very understable) or super overstable discs (playing in headwind, or short approach you want a skip and to move left (right hand backhand) right (right hand sidearm) quickly.
But most of these things will be course dependent, and also not really mechanically useful until you have played quite a bit.