are you trying to hand start it? or are you useing a starter? do you have the glow starter attached? does the plug work (unscrew it and test it on your glow ignitor)?
how cold is it outside? engines (espically new ones) do not like starting in the freezing cold. one thing to do would be to heat it up with a heat gun/small torch (dont get it to hot) and try to start it soon after
try starting with the carb 1/3 open