My Mercury outboard was simmilar.

Throttle / fast idle lever: If the engine is cold or otherwise stalling
just after you start it then a little faster idle might be helpful. So
moving
this lever a little (but not much) will help. Besides, if it's idleing too
fast
once it's started you can always move the lever back down/off.

As HL described, you have to hold the key in for the choke to be on.
Normally when the engine is cold, hold the key in while starting.
Once started you can let it out.

You might also have to adjust the idle on the engine if it's set too low.