If you have not yet reported your car stolen to law enforcement, you should do so as soon as possible. Your insurance company will want a copy of the report when investigating your claim.
A stolen vehicle claim would be placed under your comprehensive insurance coverage. The insurance company will then investigate the claim and check with the police to see if the vehicle is recovered. If the vehicle is found and has damage to it then insurance would pay for the repairs, minus your deductible amount.
State laws differ but typically your insurance company would not find you a replacement vehicle if your car is stolen, instead if the vehicle is not recovered than the insurance company will determine what the actual cash value (ACV) of the vehicle was in the condition it was in before it was stolen. Your settlement would include the ACV, minus your deductible.
If you still owe money on the vehicle and the settlement does not pay off the balance due, you would owe the difference between on your loan amount unless you had GAP insurance to pay for that difference.
If you have rental car coverage with your insurance policy, than you may be able to have them pay for a rental car while you are without a car or until a settlement is reached regarding your stolen vehicle. For more specifics about what your insurance policy allows for your situation, you will need to contact your insurance agent or the adjuster on the case.