One of the first things you should do is take any available measures to prevent further damage. For example, if the tap water is damaged then you should turn off the main tap water pipe in your house as soon as possible. If hail damages your roof, then you should put a tarp over your roof. It is important to note, however, that this does not mean you need to completely repair the damages. It means that you need to do your best to avoid additional damages.
There is always the possibility that you will face a dispute with your homeowners insurance company about the terms of your policy. Therefore, it is very important that you document the damages to your house. You can do this with photos and a written report. You need to report the damages to your insurance company immediately. Your insurance company might send an expert to your house to evaluate the damages.
If you have to repair damages before the official report is written because your house would otherwise be unfit to live in, then you need to discuss this with your insurance company. Always document how the damages are being repaired and save invoices that show the repair costs. Document any damaged parts that you throw away.