Windows 10 has a built-in Calendar app which you can use to schedule appointments and reminders, but if you are a Google Calendar user, you can still use that service with your Windows 10 computer.
To integrate your Google Calendar with Windows 10, open the Windows 10 Calendar app by clicking on the Start button and selecting Calendar from the list on the left or the tiles to the right. When open, on the left-hand side is a cog icon – click that icon to open the Calendar app settings menu.
When open, click on ‘Accounts’ on the right-hand side and then ‘Add account’. Select Google from the drop down list, just sign in with your Google details and the Google Calendar will synch with your Windows 10 built-in Calendar, allowing you to use both.
You may find that the synch times between the two may not be as quick as, say, your smartphone to Google, but you can still use your Windows 10 computer with your Google Calendar, rather than be stuck with the built-in Calendar.
You can also use other Calendars, for example iCloud too.