2009 Ford Ka Engine overheat?

Hi, I have a Ford Ka Style + and its a 09 plate. Yesterday I was driving the car and it had only been driven for about 10 minutes and the engine temp gauge went right up and the light came on, I then pulled over in a safe place and stopped the car and turned the engine off my friend opened up the bonnet and the engine did not feel hot to touch so we waited about 10 minutes and the temp went back down to normal so I started to drive again as I was only about 5 minutes away from my house. When I started driving the car again the light came on and the temp was right up so I stopped the car immediately and turned the engine off and steam/smoke started to come from the bonnet it was only about 5 seconds and it was gone. I was stopped at a roundabout so I obviously had to move the car out of the way so I then went into a lay by and the temp was still the same at the top with the light on so we waited and it went back down but when I started to drive the car again it sounded lie the engine was rattling and the temp kept fluctuating. Just wondering if you could help me as this is my first car as I've only recently passed my test. I was not driving the car fast and the car was in the correct gears for the driving situation I was in.

Thank You