The best defense is most a strong offense. A gun is a force multiplier I shouldn’t have to explain. A gun can even the odds between a 90 pound, frail old lady, and a linebacker sized thug, or a man defending his family from a gang of hoodlums. Inside your home you can utilize a long gun, a shotgun or rifle, to defend your home.
Guns end fights.
An AR 15 or a Remington 870 can keep the invading horde away in the middle of the night. Just buying a gun is not enough to always defend your family. You will need ammo, magazines, a good sling, and practice. Practice, and training. Seek out a competent firearms instructor and learn to defend yourself. Practice, be skilled at all aspect of manipulating your weapon.