Contact your Zoom admin for more information. You can still sync your contacts without a Zoom Phone license, but you won't be able to call them using Zoom. You can also sync your Zoom contacts with Google, Office 365, or Exchange, allowing you to call your contacts using Zoom if you have a Zoom Phone license. Calendar integration is compatible with Google Calendar, Office 365, and Exchange.
If a Zoom join link is not detected, the meeting will show the host information, but will also be listed as 'Not a Zoom meeting' and not have a join button. This provides an easy way to start or join your meetings. You can set up calendar integration so that your Zoom meetings and webinars on your third-party calendar are synced to the Zoom desktop client.