Take the plug out of the engine and put it into the glow driver and see if the filament in the glow plug glows. If not you need a glow plug.
If the plug is good then you may need to prime the engine. I do this by putting a few drops of fuel into the carburetor (take the air filter off first). Now try starting it again. If it acts like it wants to run but keeps dying then it could be that you need to adjust your carburetor mixture adjustments or it could be that the fuel is not making it from the tank through the fuel line to the carburetor.
Do some trouble shooting to make sure it is getting fuel. Once you know the plug is good and the engine is getting fuel then all that is left is to get the mixture adjustments set and you are good to go.
Good luck,
Lee