My two cents to people who are not used to moving their body often is to start being comfortable with your practice and not think on optimizing in the beginning. It is good to set up a clear baseline. I also recommend to have a personal trainer, someone you trust and care for you, and have real knowledge and experience training people of different ages. The personal trainer is not someone who just say what you could find on Internet but someone who observe you and make the required training changes for you.
Personally, I do something like a thriatlon training, thinking more on the mind than staying fit but fit is included naturally. My training is 3 times a week (very early in the morning) swimming training (with a trainer and a group), twice a week gym linked on "optimizing" for the thriatlon training, spinning a few times in the week and running almost all days (late). Job-wise the only think that intersect in the calendar is the gym training, the other stuff is done outside normal working hours. I used to practice Yoga and related activities and want to return to them at least once a week. My running distance timewise is ~> 5km. On the weekends I use to do ~> 10km but currently I don't care about trying with much longer distances.
BTW, I don't use earphones while running, more following a meditative running way of practice.