how far does a car have to be parked from a crosswalk?

Answer 1

That would depend on the jurisdiction. Usually ten to twenty feet is the law. This is a local issue and each city varies. Under Minnesota state law, Sec. 169.34(a), you are not allowed to park within twenty feet of a crosswalk at an intersection or in any way block a crosswalk with your vehicle.

Answer 2

Uniform Vehicle Code says 15 feet but it's a matter of state or local jurisdiction.