I don't know what learners are taught these days but my experience of this is.
A motorcycle does not have a handbrake like a car, but like wise when coming to a stop it is neutral left foot down and rear brake. It really depends on the circumstances.
Normally you would slow down mostly with front brake, this generates heat in the disc and pads, if you continue holding front brake when stopped this could warp your discs if done excessively. So a cool rear brake is ideal.
If you keep it in first gear with the clutch held in, if someone should for some reason shunt you from behind, you are going to let that clutch go and away you go into the unknown. In neutral yes you will did get hit and the bike may be pushed forward. I got hit from behind at a pedestrian crossing, I jumped forward and reved the knuts off my bike but didn't fall off. Had it been in neutral things would have been different.
As for putting your feet down, ride foot /rear brake usually. But having said that it really does depend on the circumstances, whether you are on uneven road surfaces etc. I swear by both feet down with strong winds and if I have a pillion.
It really is down to common sense and personal experience, being in total control of the bike at all times is a must, even when stopped.
Hope this helps.