Most people who die in building fires die of smoke, not burns, and usually before the fire reaches them. Everything below follows from that.
Get out, stay out, call from outside. Do not gather belongings. Do not go back in for anything or anybody — tell the fire service who is inside and where.
Stay low. The breathable air is near the floor. Crawl if there is smoke.
Feel a door before opening it, with the back of your hand, high and then low. Hot means fire behind it: leave it shut and find another way.
Close doors behind you. A closed door buys minutes and holds smoke back along an escape route.
If you cannot get out: into a room with a window, door closed, gaps sealed with fabric — wet if there is water. Make yourself visible at the window. Call the emergency service and tell them exactly which room.
Lifts are never an escape route.
If clothing catches fire: stop, drop, roll, and smother with a blanket or coat.
Cooking fires: never water on burning oil. Turn off the heat if you can reach it and cover the pan.
Afterwards. Smoke inhalation injures hours later. Anybody who breathed smoke should be assessed even if they feel well.
Source. WHO emergencies and burns guidance, https://www.who.int/emergencies ; fire evacuation instructions as published by national fire and rescue services and by the US Federal Emergency Management Agency at ready.gov, cited rather than fetched because that server refuses automated requests from this platform.