It may be you, the other driver or both that can be found at fault for this accident depending upon the whole account of how it took place. If it was safe to open the door and the other car did something negligent to hit your car that driver may be found at fault. If it was not safe to open the door into traffic then you may be found at fault. Or it could be that both you and the other driver will be found to be partially liable.

Florida is a comparative negligence state. This means that the fault of the accident may be divided between the involved parties and the insurance companies will pay the claim according to the percentage of fault for each driver. 

If you feel that the driver that hit your car was responsible then you can place a claim with the driver's insurance company to see if they will accept the claim. If not then you can place the claim through your own collision insurance, though you will have to pay the deductible associated with this portion of your auto insurance policy. With either insurance company an insurance adjuster should take statements from both you and the other driver and determine where fault will be placed.