Hi,
Could you explain a bit for your issue here?
Calculator is under Windows Accessories, we may Open Calculator by swiping in from the right edge of the screen, tapping Search (or if you're using a mouse, pointing to the upper-right corner of the screen, moving the mouse pointer down, and then clicking Search), entering calc.exe in the search box, and then tapping or clicking Calc. More information, please see: Calculator: frequently asked questions
To use Calendar, you'll need to sign in to your PC or the app with a Microsoft account. When you open Calendar, you'll see all events from your Microsoft account. To see events from other calendars, add the accounts to the Calendar app. More information for Windows Calendar, please see: Calendar app help.
If any more questions, please feel free to ask.
Best regards