Turn on the fuel.
Push the tickler down for three seconds.
Use half to three quarter choke.
Pedal up to about ten mph and release the clutch. It should fire. If it doesn't adjust the choke up to full and start back down to half. Try different throttle amounts too.
If that doesn't get it to go, pull the plug and check for spark.
Sometimes the kill switch (a lot of the time) is defective and shorts the engine out.