How do I stop ical from exporting to icloud? I'd rather have it only on my laptop.

This article is giving method to share iCloud calendars iCloud: Share calendars in iCloud

But you want to completely stop sharing iCloud calendar see these screen shots .

( a ) open system preferences internet accounts > select i cloud drive and more the calendar box is checked , simultaneously open calendar app through spotlight , you can see iCloud calendar .

To un share ( you used the word export ) the iCloud calendar uncheck the box of calendar and hence the complete calendar application and it data will be disconnected with iCloud server temporarily , it doesn't mean the calendar data will be lost it is saved on the server , its just an a configuration .