Just make sure the bolt on the blade is tight..... it should be ok... but make sure the blade is in one piece and equal lengths from center

That inner handle is a clutch, not a throttle.
The newer engines like that are single speed, to start it you just need to push in the primer bulb about 3 times (mine doesn't even have a primer bulb).
Then squeeze the inner handle up against the outter handle with your left hand.
Last, pull the rope( with your right hand while keeping the inner handle squeezed up against the outer one with your left), hopefully only about two or three times

To stop it, just let go of that inner handle, the clutch tension will stop the engine.