If you're new to handguns a revolver might be a good choice for a home defense weapon and one to familiarize yourself with centerfire weapons. A good used Smith & Wesson Model 10 or 64 .38 Special or Model 19 or comparable .357 Magnum--you can shoot .38 Special ammo in the .357, and that would be a good idea to learn the ropes. The manual of arms and maintenance of a revolver are much simpler that those of a pistol, and the right .38 Special ammo is fine for defensive use.
You can always trade up for a different weapon later--demand for Smith revolvers is always good--but you might just find you like a wheel gun a lot.
Whatever you get, if you are looking at a used gun, have a good gunsmith check it out.