What is the maximum amount of people on a family tree

Answer 1

There is no limit in amount.

Answer 2

There is a limit on the size of a GEDCOM file that can be imported. It used to be 16MB. I don't know if it still is. There is also a limit on how "far away from you" you can enter new family members. I don't know how far away from you that is. There are people who have trees with over 10,000 members.