Even if the fire department doesn't declare your property damage to be "catastrophic," the aftermath of a house fire is devastating. It's hard for property owners to know what to do once the fire marshal leaves, and you're on your own.
It can sometimes take days for your insurance company to send out an adjuster and suggest a restoration plan, but you don't have to wait. It's beneficial and advisable to contact a fire damage restoration company like ServiceMaster immediately. They'll be there within an hour to help you figure out what to do next and how to talk to your insurance company.
Because smoke damage creates a highly toxic living environment, very often you'll need to temporarily relocate until at least some smoke/soot cleanup is performed. If possible, salvage and pack any valuables or important documents (insurance policies, financial records, etc.) to take with you.
Do not touch anything soot-damaged with your bare hands; fire residue is a biohazard. Do not use electric appliances until they've been assessed for safety. If you still have power, make sure your HVAC system is off so the smoke and soot doesn't spread through to unaffected areas of the house.
Our family and crew has been helping residents for decades if they ever experience a property loss caused by fire.