How do I edit the name and emoji of a calendar?

From OurCal's Calendar tab:

1. Tap the Filter button in the top right
2. Tap the info icon next to the calendar you'd like to edit
3. Tap the emoji & name row to edit
4. Tap Done to update

Please note you can only customise the name & emoji of calendars added to your calendar group. Your group's default calendar and member calendars cannot be edited in this way.