You have a couple of options! The most important thing to keep in mind is that the car cannot be driven at all without insurance. If you don’t plan to register or drive the car right away, see if the current owner will bring the car to you. This way, you won’t need to worry about coverage for the drive home and you can get insurance whenever you’re ready.
You also have the option of using a storage plan. Some carriers will allow you to have just comprehensive coverage to protect your car from perils such as fire, theft, and vandalism. This will save you a good amount on the premium, but be aware that the car cannot be driven with this type of policy.