[I would also start by cleaning the carbs. A plugged pilot jet will cause it not to idle. Then have all the carb settings adjusted to spec. As far as the choke goes there must be something missing it should stay on by it self. Being new to carb work I would get a good manual and follow it. These...
If your tank has a flip open lid over the gas cap then the hose conection under the tank in the middle is a drain for spillage whe gas is put in. It needs a hose going from there to behind the engine and draining to the ground.
tools
The 76F tool kit; sparkplug wrench
open end wrenches 10x12 & 14x17 (mm that is)
pliers
straight screw drive
philips #2 & #3
tee handle for screwdriver...