You can definitely use the F lounge on arrival if flying first. I use it all the time from my long hauls connecting to either Milan or Lugano.
They will also take you by car to the plane if it’s on a stand or escort you through immigration etc if the plane is at a dock.
On entry most people turn left, but the lounge to the right is quieter and to the same standard. You can also use the Long Bar to while away some time in the Business lounge, but with direct access from the First lounge.