You don't. You sue the individual. The insurance company is obligated to take care of the obligations of the individual.
You need to hire a lawyer if you want to sue someone. You need to try to settle this first by yourself by calling the other person's company and see what they say.
You can.
The person who causes the accident is at fault
If your insurance company pays you, they will sue the at-fault driver and hopefully collect or force them into bankruptcy.