If your parents are/were both only children, then you will have had zero first cousins. If they both came from large families who produced many next generation offspring then you may have hundreds of first cousins.
For clarity’s sake this poll is for a count of the number of offspring of your blood uncles and aunts on both sides of your family. Not step-cousins unless they are the offspring of a blood aunt or uncle. Not first cousins once removed or any of that. Just plain first cousins.
You don’t have to do an actual count. A reasonable guess will work.
An example: On my mother’s side there are three. On my father’s side there are nine. So my total number of first cousins is twelve.