My dad is 53 & both his dad & G~pa died of heart attacks before retirement. Now he has had a collapsed lung?

Get an appointment for your dad with his doctor asap. Make sure that everything you listed here is communicated to the doctor (write it down so your dad doesn't forget anything). If the hospital didn't refer your dad for cardiopulmonary rehabilitation, ask the doctor about getting a prescription for that. It sounds like your dad needs to get regular exercise, and based on what you shared about the Chinese restaurant, it needs to be medically supervised at first. Finally, if your dad is a smoker, he needs to stop immediately.