Serves engina soon light come on

I have a severs engaine light come on what does that mean on a 98 pontiac bonneville can any one help me and my heat and air conduction don't work at all.

When the service engine light comes on, it's telling you that one or more of your electronic sensor is bad or out of specification. The only way to check that is out is to scan the vehicle for codes. Once the code is retrieved, it will direct you to the problem area.
Good Luck.

Find a parts store that will scan for codes at no charge. They will do it.