Hello @Karen816,
One option is to add a private note for the date or dates.
To do this go to your calendar and click on the date.
In the box that appears in the right click on "Add" in the "Private note" line and add a note.
If you want the note to apply to several dates click to the right of the arrow in the "Selected dates" box to specify an end date.
Then click on "Save".
The screen shot below shows the box that appears and the "Family staying" not that I added previously.
Steve.