S.I.N.G. is my go-to first self defense lesson for my friends. Solar plexus, instep, nose, groin. Solar plexus is great for stunning someone, instep to break the foot, hit up into the bottom of the nose, then hit the groin for good measure. While the assailant is recovering you run and call for help.
If someone grabs your wrist, break their grip by jerking towards their thumb. The thumb isn’t nearly as strong as most people imagine.
If you hit someone in the temples on the side of the head with your palms, you can disorient them. I’ve seen children do this to adults.
If you have your keys in your hand for self defense, a punch is more likely to break your hand; instead slash with the keys like wolverine claws.
Many martial arts studios will offer a free self defense lesson to entice new students.
Source: 3rd degree black belt