Of course there are still sculptors around! Like most art sculptures have gotten more abstract tho. Visit any museum of modern Art and you are sure to find some!
Marble and the like are of course incredibly expensive, and for that reason most people stick to more affordable options like wood or ice. Or do additive sculpting with clay/plaster, welding or something like that. If you really want to work with stone you might want to apprentice with a stonemason.
How did I start? Took a pocketknife in my hand and started whittling. The foundations of working in a subtractive manner are largely independent of material.