Dashboard Lights

I just got a 01 Sunfire SE it has just under 17k miles, and the coolant level, service engine, and airbag lights are all going on and off as they please. I have had the sensors checked, and they all seem fine, I am totally clueless when it comes to this stuff. What could be causing these lights to go off and on? PLEASE HELP! It freaks me out seeing the SES light on.

i have a 2000 sunfire and theres one thing that i have learned, their computers are the biggest pieces of shit and the sensors like to go off pointlessly, i have replaced my o2 sensor and my engine light is still going off because of it. so i still haven't figured out what to do that wont cost me a fortune so if u come up with any ideas please let me know.