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.
Well said, but I believe the OP needs to understand something, once you can afford a thing, you shouldn't regard yourself as poor again as poverty is relative, one should carefully use it. Most people who consider themselves poor are not actually poor, they don't just have the financial freedoem which I believe they should continue to strive for.
Emphatically, saving Bitcoin as you have the capacity will go a long way, but ensure that it's regular, and before you know it, you might have had so much BTC in your wallet. Note that Bitcoin is always neutral to all, just find the right wallets that can accommodate the little BTC you can afford. With this advice, the supposed poor person might painstakingly gather more Bitcoin if determined more than the supposed rich people, it's a thing of mindset and how you place your priority.
It's never a crime for the less privileged to save more than the rich, he should just have the will, do his bit and be consistent.