The education required to become a state trooper varies by state, but in general at least a year of post-high school education is required. In some states, if you have served in the military the post-high school educational requirement is waived because of your experience.
You can enroll in Medicare Part D coverage once you meet both of the above requirements. Your Initial Enrollment Period for Part D is when you're first eligible to sign up for prescription drug benefits, and this period usually coincides with when you're first eligible for Medicare coverage.
Medicare Part D open enrollment for a person with traditional Medicare (Part A and Part B) runs from April 1 to June 1. A person who wishes to switch their Medicare Part D plan to a different insurance company can do so from January 1 to February 14.