it depends on their laws
no
18
That depends on factors such as the language of the court order, the State, whether the child has a severe disability, the child's school status, etc.
If either parent lives in New York or if the child lives in New York then the judge can order a paternity test.
In New York State the maximum age for child support is 21 years old. However that is considered "emancipated" if the child gets married, becomes self-supporting, or joins the military.
Yes. see link
When they turn 18.
the one who did not abandon the child probally
Right after the child turns 21
21 or 18 depends
yes, even if you never knew you had a child.
The answer to this child support question and many others for the state of New York can be found here. https://newyorkchildsupport.com/