Hey Daren!
do I have to upgrade to Events Calendar Pro before I can purchase and install iCal importer? Or can I just purchase iCal importer and install with the standard / free version that came with my template?
You do NOT need to buy Events Calendar Pro! You can definitely just keep using the free / core version, The Events Calendar. Events Calendar Pro is not required.
However, I would recommend DELETING the version of The Events Calendar that comes with your theme, and instead just installing The Events Calendar directly on your site fresh from its official download source, which is here:
• http://wordpress.org/plugins/the-events-calendar
☝️ The reason I recommend this is because plugins that are included right inside themes can be out-of-date. This is a bad coding practice and so I would recommend replacing the theme version with the official version from WordPress.org as linked above.
Ensure you are using the most recent version of The Events Calendar (currently 4.2.3), and then go ahead and add iCal Importer! 😀
I hope this information helps.
Cheers,
George