Karate is a sport, if you’re serious about self defense, I’d highly advise something else.
When you go into an area of uncertainty, trust your gut instincts. Man has battled man for thousands of years. That gut instinct is part of survival. That instinct will normally guide you away from danger.
Do not show fear even if you are scared shi-less. Once you show fear the pack senses weakness and will attack.
If escape is possible, run like hell.
If you are in an enlightened state like my Texas, always carry anyplace it is legal. I do, and 458 foot lbs of energy from a 9mm Powerball ammo makes a very heavy statement on a bad guy. If it is a group take out the leader first.
Relative to carrying a weapon, when you are carrying it gives you a sense of confidence that potential muggers will pick up on. Look them in the eye with confidence and they will pick up the sense not to mess with you. It really is instinct. The bad guys also have instincts. They will move on to an easy target.
The best gunfight is the one that did not happen.
If it all goes to hell and you must use your weapon do not brandish it nor threaten to use it. Once you pull that weapon out the decision to use to survive should have been made. Use it until the bad guy is down.
Again I repeat, “The best gunfight is the one that does not happen.”