Google Calendars require a Google email login. If you are in a browser on a computer, above the gear icon are the google apps 9 dots - open this and find Google Calendars.  On the left-hand side, under 'My Calendars' there is a drop-down menu in which 'Create New Calendar' can be selected. Do so. You can name it and then share it with others. At the bottom of the page, 'Create Calendar' will finish the process.