Monday Hour One with Business, Employer, and Personal Items

I’m starting my Monday Hour One ritual today and am having a hard time determining the best way to accommodate for scheduling all of the items on my list. I have an employer where I have meetings/calls scheduled and sometimes are pretty last-minute (Although my schedule outside of this is pretty flexible)I’m also an entrepreneur and have tasks for my start-up and, of course mom, wife, family, friends stuff. I had been using multiple calendars previously to break up these tasks into different calendar buckets, but that’s hard to stay on top of and keep track of 3 different calendars. I’m hoping to simplify and use 1, but am reluctant to keep everything on the calendar that I use for my employer. Any suggestions or best practices you can offer in this case?