Hi Flora,
Thank you for using Cvent Community!
Event Calendars is moved to the Events view tab now (from the Admin tab previously). You need to hover over the Cross Events drop down on the top left and click on 'Events Calendar (New)' option. You can then click on the Additional Calendar Items tab to Create or Import Additional Calendar Items.
For additional information please refer to the article on Adding New Event Calendars (https://cventhelp.force.com/apex/apex/CommunityArticle?id=000044932&Lang=en_US).
Hope this helps!
Regards,
Kimberly S
Sr. Client Success Consultant