To start a motor all you do is put in the glow ignitor, and pull the string. But first you have to prime it: put your finger over the exhaust outlet and pull the string about 2-3 times.
It should take you about 7-8 tanks before you start to fine tune the engine but it really takes about a gallon to fully break-in an engine.
There are lots a ways to turn the engine off: put your finger over the exhaust outlet (it aint that hot be a man), pinch the fuel line, stop the flywheel with the tip of your shoe (wear your work shoes), and you could just let it run out of fuel.