My 2000 sportsman 500 will not start off the push button and the lights will not work, and it is overheating which is something it has never done. Any clues as to what might be wrong  

I would check your wiring first being that your having the light issue and the start issue.

Does the starter turn over when you use the push button?  

Starter will not turn over at all. Someone mentioned to me about a fuse up under the front headlamp, but I can't find one. Any idea where it or they might be?  

For the owners manual click here

If you look on the last page I believe that is where the wiring diagram is.

There are several fuses, including a circuit breaker right off the starter solenoid.

Get yourself a Multi-Meter and place it Ohms scale. Use it to figure out where the fuse is blown.

Hope this helps you