Lots of people paint or draw - it's easy to pick up a pen/pencil and go for it. Not many people sculpt - that takes a lot more effort, particularly with stone. Clay and other mold-able stuff is easy - you can fix your mistakes. Not so with stone, you cut a piece off, it's gone.
I took lessons in carving stone. You pick a piece of stone that is slightly bigger in all dimensions than your piece - perhaps something that looks interesting. Perhaps you make a drawing or two to help you think about what you want. Then you start chiselling away until it's in the shape you desire. There are several kinds of chisels - teethed ones that are easier, but leave a rougher surface and smooth ones that leave a smoother surface. Once you have the right shape, any part that you want smooth requires a lot of sanding. You start with a rough sandpaper. Then sand again and again and AGAIN, each time with finer grit. Finally you cover the thing with wax to shine it up. Hopefully it will look good.
Note carving stone takes a LONG time. Much quicker to draw or do some kind of casting (see life casting and metal casting). It's not a quick afternoon hobby, but more like a month long project - at the minimum.
The main reason it is expensive is the time - even small projects take forever. This is not easy, but not particularly hard - if you are going for an abstract look. If you want something that looks exactly like an existing object/face/body, then it will be a lot harder to do. It can be a bit tiring, particularly when you are at the hammer and chisel phase. But it's not really a work out.
Genderwise it is pretty neutral, the same goes for age. Kids can do it fine.
I took lessons and bought my materials at "The Complete Sculptor":