The definition of "personal protection" can vary on your location.
If you are planning on personal protection outside the home, obviously a handgun would be the choice, and a revolver is the way to go if it's your first handgun. (I would recommend a revolver to anyone, btw, not just "first timers." The advantages are many, the disadvantages few).
A lightweight hammerless .38 is ideal for a man or a woman. Forget all the advice about getting a full size .45 auto etc - ask whoever recommends one where their handgun is. If they say "in the glove box" or "at home" then you will know why it's not the best choice for carry - it's big, and it's heavy. And even the smallest .25 auto in your pocket is better than the largest .45 ACP that's not with you.
In your home, a handgun is what you would use to fight your way to a real gun.
A short-barreled 12 gauge semi-auto shotgun loaded with 0 or 00 buckshot is my choice.
But there's also nothing wrong with choosing a rifle like the AR-15 (.223) other than you need to be sure you hit the perp or the bullet could end up in you neighbor next door.