I the was working with the gas line and the electricity and I turned off the gas and electricity of the furnace and after I was done working with the gas I turned it back on and the furnace fan turned back on and when I woke up I found that there was no heat coming out the furnace I checked the terminals w and c and there is no 24 bolts and also no electricity in the red and white colored lines that go to the thermostat what can be wrong with my furnace

You may have a bad transformer. Check the input and output on the transformer and see if you have voltage. I don't know whether you have a 120 volt or 240 volt furnace. Many are 120 volts, but if you need a transformer they sell ones that work for all voltages. You just have to use the right wires to hook up the primary voltage. When you are reading at the thermostat, between R and W you will read zero volts if the switch is closed and 24 volts when open, but between R and C (common) you should read 24 volts. R supplies voltage to be switched on and off to W on the thermostat. C is common, the other side of the circuit. C and W go to gas valve. R and C are the secondary terminals (output) on the transformer. Let me know what you find. DrTom4444