I think our culture is so used to "consuming" that we forget to create space for "allowing."
I used to go out to eat by myself all the time, and I would bring a book (or scroll on my phone). One time I forgot both at work and just looked around and people watched. Ended up striking up a conversation with some folks at the next table and learning so much about the road trip they were on and what they had seen and done... And while it wasn't a life changing conversation for me (that I know of), it was definitely neat to connect to strangers ,and something i would not have done if I were engrossed in my book or social media.
And I'm with you RE a free calendar. I intentionally space out my social stuff to allow for plenty of downtime in between whenever I can.