Ijust purchased a new furnace, an American standard with Intell Ignition control (50A65-476). I am only using it as a furnace, no heat pump or air. The old furnace used a two wire thermostat. The new control has twin-Y-W-R-G-C. Which do I need and which if any need to be jumped to use the furnace.

You will use the R and the W terminals on the thermostat.

The only jumper you might need is if you have a Rc and Rh terminal you might connect them if they are not already jumpered. You should not have to do that since you are not using AC.