You can cook in a fireplace if the chimney is sound. Don't start a fire in a fireplace that has a broken chimney. Be sure the damper is open. If you're cooking on a wood stove, make sure the stove pipe has not been damaged. If you have to build a fire outside, build it away from buildings, never in a carport.
Sparks can easily start a house fire.
Never use gasoline to get a wood or charcoal fire started. Make sure any fire is well-contained. A metal drum or stones around the fire bed are good precautions. A charcoal grill is a good place in which to build a wood fire. Be sure to put out the fire when you are through with it.