Contact your insurance as quickly as possible after the fire. They will send an adjuster to your location to inspect the damage and to make a report. This person starts the claim process and will give you help etc.
All Insurance companies have a 24-hour emergency number.
Remember to leave your contact number / information with the Fire Department officer on scene.
When the F.D. / Police have finished their work, you are now responsible for the building. You must protect and secure the building to prevent robbery or anyone being injured etc.
Do you need to store any items in storage or with family or friends?
Make sure all utilities are turned off if the house is not habitable.
Remember, you are responsible to board up the premises to prevent any injuries or damage.