What cause heat hand show hot when it's not?

Bad gauge sender or even a bad gauge can do this. Live data should be able to tell just how warm it is running. If live data shows it's operating at proper temperature, then focus on the gauge circuit itself and that includes the sender, wiring and the gauge.

I'm sorry me or my boyfriend doesn't know whole lot about mechanic work know a little what exactly is live data? and then how do I tell if it's it the gauge circuit the sender, wiring or the gauge what do we do to check it? is there a tool or something we buy to check these things ? any help would be greatly appreciated

Live data is what the computer is seeing from the sensors and its responses to that data, to access that stream you need a good scanner. but there is a catch 22, you need to know what you're looking at, but as you stated you don't know much then it could be a waste of money for you. Now something that could help is buying a decent shop manual, it should contain wiring diagrams, component locator, and a section on code diagnosis. A factory one would be ideal but this old that is probably an impossibility, I would try EBay or even your local parts store, stay away from Clymer manuals. I did get a good by one time for an online manual that I still use today, be very careful about who is supplying them as you could get ripped off. HTH

Is the coolant freezing up ?

Check the wiring and the connector going to the coolant temperature sensor. You might have a bare wire that's touching something metal. This will cause a false hot reading on the dash temperature gauge. Another thing is the heater blowing hot or cold air? If it's blowing cold air that points to air in the cooling system or a very low coolant level. Make sure you fill up the radiator to the very top, when the engine is cold, first, then fill the plastic coolant tank to the full cold line on the tank. Jim