Are you in San Francisco proper or more towards San Jose? If San Jose, I know an excellent instructor there who has trained dozens of aircraft owner pilots from zero hours to their certificates in the high performance hot rods including Mooneys. It can be done and done safely with an experienced flight instructor who can see your mistakes coming and is able to prevent them from causing aircraft damage. Absolutely learn in the plane you will own. You will be far more experienced in it when you are flying solo and with passengers, and you have the benefit of making the new-in-type mistakes with an instructor who can show you how to correct and prevent those mistakes.
If you find an instructor that doesn't know how to land a Mooney safely, nor teach you how to land without flat-spotting tires, porposing, and other costly mistakes, this will not go well and you are better off learning in someone else's plane.
Welcome to the aviation world!