When I press F2 the save as menu opens
I realize this is an old question, but in case anyone else needs an answer ...
The "F2" in the video isn't referring to the F2 key on the keyboard, but rather to a plugin called "F2". It's included in Blender by default, but it's not activated.
You can find more information here: https://docs.blender.org/manual/en/latest/addons/mesh/f2.html