You can set up a Google calendar once you register for a Google account.
Google will provide you with the code to embed the calendar in your website. You will copy and paste their embed code into an "Advanced - HTML Code" section on the page(s) of your choice. There are a variety of display options for your Google calendar, for example, monthly view, agenda view, etc.. Be sure that you choose the one that you want. Often people choose agenda view for their panels and the full monthly view for their calendar page.
You may wish to turn on the "Responsive" option for the "Advanced - HTML Code" section, which will give better performance across various devices.
The following article from Google may be of assistance:
https://support.google.com/calendar/answer/41207?hl=en