A center fire revolver to fill a beginners needs would be a 4” 357 with adjustable sights. 6” is to long for practical CCW and frame bigger than K is added weight. Both would be the better range gun but that’s not what OP is looking for. I would look for used m19 Combat Masterpiece 4”, Ruger Security 6 4” or a Colt of similar size. I would hesitate to suggest Taurus or Charter Arms or other 2 rate firearms. Would never buy used and for new money could find a good top shelf used. Would go with 357 only because you can use 38sp too. With 9mm easy to find at $11-$13 box of 50, 38sp running close to double that. 357 is crazy. Ammo manf only got so many machines and they can sell all the para military ammo they can pump out. They don’t want to shut down to change tooling for cartridges with limited sales. The way the political situation is, I don’t see any changes in near future. Maybe a 9mm 4” revolver would be perfect all around revolver.