I started out with the Nikon NX or whatever it is. Then I tried GIMP which worked pretty well with a learning curve involved. Then RawTherapee (a big learning curve). See the trend ..FREE software. Then I purchased Adobe PS Essentials which worked well but was limited. Finally, I have settled on ON1 Raw which works well for me now. It can be purchased, or it is available through subscription. I said I would never do the subscription, but I did and if you decide to drop it later, the software you have is yours to keep/use.
Start with the free stuff and as you get some experience under your belt decide on something to purchase.