The first thing you obviously should do when your car catches on fire is get yourself out and any passengers as quickly as possible.
Then from a safe distance call 911 and stand back and await the fire department to arrive.
It's best to not try to put out the fire yourself unless you have a fire extinguisher and the fire is just a very small fire.
Otherwise just get out and get away and call the fire department.
A car can be replaced but humans cannot. So always get yourself and any passengers and especially kids such as babies or toddlers that are in child restraints out of the vehicle first.
Any older kids should be able to get out by there self so tell them to get out and then go get any infants or toddlers out of their child restraints while the older kids are getting out if you have infants or toddlers in child restraints.
If you have too just take the whole child restraint out with the kid in it. Just do whatever is fastest at getting the kid/kids out of the vehicle during a fire.