Whats wrong with my car

What is your question?

Today my car jus overheated for the second time, the fist time this happened the low coolant light was apearing and then disappear from time to time, then the belt that turns the fan went dead on me and I had it replaced , now the service engine light would appear and then disappear, now today when I got in my mar this morning everything was fine drove it to work and had it sit for 6 hrs untouched. Then all of a sudden I get in to go get an oil change for the fist time owing this car it all of a sudden over heats I have been adding coolant as it runs out but there are no signs of leakage when parked ... What could be the issue b4 I get to the repair shop and they try and give me the run around on things ... Help please ...