How did old people should be tackled?

'Head on' !!

Be careful you don't knock them down!!

Are you refering to the way you speak/listen to them?
Just be natural +speak/act the way you normally would.

If you mean, How do I handle or approach them, the answer is, like any other person. Though you may not comprehend it now, before you know it you'll be older too. And wondering why young people are so different from you when you were young. I'm 62, probably old to you, but I still feel like a young man especially when I look in the closet and see my old Marine dress blues. Still fits. Before 20, two combat tours in Viet Nam. So, don't stress any infirmity, many respond to your type of language, love music, dancing, maybe strong beverages, or still smoke a little weed, love sex, fast cars and money. Any different from you? Parents always seem difficult and old. Mine sure did. So, forget the apprehension and remind yourself that we're just kids in older clothes.