If you are concerned about security, the new scheme where Apple cannot see your contacts, calendars and photos, but it isn’t super easy to move things. So here’s a quick list for how to do it.
Moving Contacts
There are really two steps to move your contacts. First go to google.com/contacts
 and export the contacts into VCF format. Then logon to iCloud.com
 and go to Contacts and click on the lower left gear to do the import.
Now to actually use them properly, you need to go to each iDevice and make sure that in your contacts setting, it says you are using iCloud
 for contacts and not Google
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