Hi Florence,
Apologies for the inconvenience with the Calendar. I have tested with a manual account and the instructions are correct but when I log in as you (and a couple of other students) I cannot see the option as you report. I will create a call and have it investigated.
In the meantime, you can access your calendar from any page by clicking on your name/profile picture at the top right hand corner or the screen and clicking on My Calendar in the drop down list that appears.
Wesley