My landlord sold the building in which I been living for the past 16 year's now she want to buy me out I will like to find out what is the amount to ask for and what are rights as tenant thank you.

First you don't have to agree to be bought out, you can require them to allow you to stay to the end of your lease. But at the end of the lease, they may ask you to leave with nothing extra.

So how long is left in your lease, if there is 10 months, you should get more than if there is 2 months.

If it was me I would start with the cost if there will be an increase in your rent if you move, and the cost of the move itself.