One of the sensors detected a fault that occurred at least 2x, but there are about 100 different ones. you need to retrieve codes from car's comp with a code reader
Check your fluid levels.
it is low or out off coolant.
You start by having it checked for codes. The light comes on because the computer has detected a fault. You need to know the code to know what to repair.
Fix the problem causing them to be on.
YES
There is an engine misfire, probably spark plugs issue.
I am not sure of the other 4 reasons But in my experience the top reason your check engine light comes on is because your gas cap isn't tightened all the way.
To reset the check engine light unplug the battery for 30 minutes. If the issues still persists the light will still light up when reattached.
Get the computer scanned to see what the problem is.
The light came on because there is a problem with the system. Your local auto parts store can read the code(s) set in the vehicles computor. The codes will lead you to the problem.
check for a bad door switch.
Bring to a shop that has an ABS scanner to determine problem or clear codes