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

From OurCal's Settings tab:

1. Tap Calendars
2. Tap theℹ️ Info icon next to the calendar whose name you'd like to edit
3. Tap the name of your calendar
4. Edit it's name and tap Done

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.