You would file the claim for the damages to your car under your collision coverage since you collided with your carport. The deductible associated with this part of your physical damage coverages would be due for your car to be repaired.
As for the damage to your carport, it will depend upon the terms of your auto insurance policy as well as state laws but likely it would not pay to fix your own property. Property Damage liability coverage usually covers you if your car damages someone else's property. Usually it is their car, but it could be a fence, a house or any other property damaged in an accident.
If you damage your own property then your auto liability insurance may not pay out. The concept involved here is commonly referred to as a household exclusion. The mandatory liability coverage on your vehicles protects members of your household against claims brought by people who are not part of the household.
You can speak with your car insurance agent to see if the terms of your policy and their guidelines allow you to make a claim for your carport. If your auto insurer does not accept your claim for the carport then you should seeĀ if you can place a claim for the carport damages under your homeowner's policy.