After your car accident you'll need to exchange drivers information. Give the other driver your insurance information and get there insurance information from them as well.
You'll then need to get an estimate of the repairs on your car from a few different auto repair shops.
Then take the estimates to your insurance agency. In this case Allstate. Then the insurance company will get things rolling and should process your insurance claim and get the repairs covered or write you a check to have the repairs covered.
You'll have to pay a deductible as well.