Time Management is just what I need

Dear Brooke and Team,
I’m excited about learning April’s work. I have found a thought that often holds me back from planning is FOMO! I fear that I will loose out on things that may come up if I’m too rigid in my planning, so I have a To Do list as a guide, but more often than not, I would do the things on my list, but I leave flexibility in my schedule in case some things come up. My question then is how do you account for stuff that comes up without your planning? For example, sudden illnesses — yours or your loved ones that requires your care and attention? Opportunities to do fun things with friends or family?
My second question is what kind of calendar do you use? Do you have a preference for a particular type?