That sounds like a nt speed carb with a gas shut off. The metal lever is the choke, lifting it up is choke applied. What I do is 1. Turn the fuel on and hold down the primmer on the lift side of the carb for about four seconds 2. Lift the choke lever and pedal to six to seven mph and release the clutch 3. When the engine starts firing I lower the choke slightly and stop while the engine warms 4. Once it warms to where I can lower the choke fully I pedal up to speed and then release the clutch. Enjoy the ride!
P.s. the white lever handle is on when it is aligned with the fuel line, off at a 90° angle.
Is the picture below your carb?