The key for my car spins freely in the ignition, and the car won't crank.
It sounds like your ignition switch has broken. This switch has the detents in it that give you the different positions that the key goes through (e.g., Off, Accessory, On, Crank). This switch breaking explains why your key would be freely spinning. I would ask for help from one of the mechanics at YourMechanic to help you replace your ignition switch.
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