What is the minimum amount of bitcoins a poor person should have? and the minimum time it should be Hold/retained?
The term "poor" is almost as broad as what "rich" is.
It will all depend on what the capabilities of that person are financial-wise. I mean I can consider myself a poor person because I'm having a hard time budgeting my monthly salary. At the same time, a person who has a lot of money can consider himself poor as well. A person can buy a single Bitcoin, and consider themselves poor still. Like other users here, I can't say a specific amount as well because this question is kind of irrelevant.