General etiquettes one should have while meeting a person with physical disability

What are the general etiquette that i have to follow when I meet a person with physical disability for the first time?

Never ask about his or her disability at the first interaction. Let the conversation flow and the story reveals itself automatically. Don’t bend down to talk to a person who is in the wheelchair. If you want to talk to the person for a long time, get a chair and sit comfortably near him or her. Don’t push a wheelchair without prior permission. People with physical disabilities consider the wheelchair as an extension of their body.