Yep, use a tiny screwdriver - the screw is in the center of the throttle arm.

There might be a few different thoughts on this, but my feeling is to get at least a couple of tanks of fuel through the engine before messing with the low end needle. The low end 'mixture valve' comes 'set' at the factory; it's usually set rich, but is at least set to where you should be able to get the engine running and idling reliably and have just a bit of hesitation with acceleration. The low end (in my opinion) should really just be a fine tuning of the acceleration.

Having the engine running on the rich side won't damage things, but running it too lean will.

And don't feel stupid - there is a lot to this hobby, especially when doing it on your own. It wasn't that long ago when it all seemed totally foreign to me. I started up my 46AX, thought it was insanely loud and powerful, and now it feels and sounds like a toy to me Ask away!