The short answer: If you are completely new, start with a set. You get discs that work together, often with a bag, and you can get out and play straight away. Read more in Which disc golf set should you choose as a beginner? If you already have a set, try a few different discs of each type. It is the quickest way to find out what suits your throw.
Disc Golf Starter Pack 1What to look for
Discs come in four types. Putters are for putts and short throws in towards the basket, midranges for approaches and controlled throws, fairway drivers for drives where you want to hit a particular line, and distance drivers for the longest throws. The faster the disc, the more speed you need to give it before it flies the way it is built to.
When you buy new discs, get a few at a time and give them a few rounds before buying more. You learn more from throwing the same disc many times than from carrying lots of different ones. What the numbers on a disc mean is covered in What do the numbers on a disc mean?
Your next discs after the set
Another putter
Many players carry one putter for putting and another for approaches. A slightly more overstable putter like the Discraft Zone resists wind and finishes reliably at the basket, so it complements the putter from your set well. More picks in Which putter should you choose?
ESP Recycled ZoneA midrange
If your set has no midrange, one is an obvious next buy for approaches and short holes. The Axiom Hex is our best-selling midrange and flies straight with a gentle turn and a soft fade. More picks in Which disc golf midrange should you choose?
Proton HexA fairway driver
A fairway driver that behaves a little differently from the one in your set gives you more options off the tee. The Latitude 64 River has lots of glide and gives easy distance. Hold off on distance drivers until your fairway drivers fly the way they should. More picks in Which disc golf driver should you choose?
Opto Orbit RiverA whole world of editions
Once you have found the discs you like, there is a whole world to explore that is mostly about looks and style. Many discs come in special editions: first runs from the first production of a new disc, signature discs and Tour Series with a player's name, and plastics with effects like glow, which shines in the dark, and halo, where the rim is a different colour from the rest of the disc. So the same disc comes in many different editions, and the difference is mostly in the looks, while the disc flies much the same.
Have a look at Special discs, First Run discs, Glow discs and Halo discs.