OK, Denis, it sounds like urban self-defense is one of the things you are interested in. If guns are not possible for one reason or another, what kind of weapons can you carry or have at home? Knife? Sticks? Swords? These are proven tools of destruction. Not as convenient and powerful as a firearm, and require much more training and physical ability. But they work. Find people who can teach you to fight with them. Usually dedicated students can become lethal and effective against untrained people in a few years.

Situation awareness is a great weapon, and it's something you have to carry with you almost all the time. A weekend self-defense class won't give you that. You need regular, frequent, and prolonged exposure to a mock combative environment. But this is a big commitment.