How do I clear overtyped entries in Calendar app?

Please tell us what version of macOS is installed on your Mac.

Have you checked for and applied any available OS version updates? (Not upgrades)

It's apparent that you are looking at several different calendars there in the Calendar app.

Have you tried disabling the viewing of certain calendars to see if the display cleans up. You can find the different calendars listed in the sidebar on the left. If you don't see the calendar list, you may need to enable viewing of the list by clicking the "View" icon at the top-left corner of the Calendar window.

Calendar User Guide for Mac - Apple Support

Your video is very informative. 👍🏽

Obviously the problem appears to be some conflict between the Apple and Google calendar events.

Have you reached out to Google support for guidance?

The fact that this continues to happen in safe mode suggests that this may (or may not) be more an OS problem than related to any installed software, as safe mode would typically prevent most third-party interference.

I see an icon for CleanMyMac in your menu bar. Has it been installed long?

The odd behavior of the Calendar app could easily be caused by an app of this type (cleaner/optimizer). These apps are not needed on the Mac and it is generally recommended not to install them. High on the list of rules to keep a Mac running smoothly is "Don't install junk."

CMM is particular notorious and has been implicated in so many problems that are reported here in the community that many veteran users consider it to be malware itself. I've sworn off the app myself after it caused a major problem for me. I recommend you uninstall CMM per the guidance given by the developer. https://cleanmymac.com/faq/how-to-uninstall-cleanmymac

Unfortunately, even if you follow that guidance to the letter, CMM may leave bits here and there. There are other apps that can finish the job if need be.

In addition to cleaning/optimizing apps such as CMM, it is also advised to stay far away from anti-virus and VPN software as well. If you also have any of these installed I advise you to remove them.

Have you restarted your Mac lately?

Rebooting is the best first step in troubleshooting.

If a simple reboot of your Mac doesn’t fix things, see if the problem still happens in safe mode.  Safe mode will often correct weird software behavior by forcing the OS to clear caches, do disk repair and other self-maintenance and housekeeping and temporarily disables third-party mods.

How to use safe mode on your Mac - Apple Support 

TIP - Use a wired USB keyboard for this. If you have the Magic Keyboard, plug that into the Mac with its charging cable. Wireless keyboards may not respond quickly enough to put the Mac into safe mode.

Does the same thing happen with Calendar while booted in Safe mode?

You can exit safe mode by restarting your Mac normally, then reevaluate the problem.

The vid that you linked to is marked private and inaccessible.

I do understand and see that the text of your calendar events is overlapping. This is why I suggested unchecking some of the calendars that are displayed. If you can discover which calendars are affecting the display, then you may be able to resolve this.

In this pic you can see that I have several calendars from "iCloud" check-marked and visible, and a couple "Other" calendars. If I remove the check-mark then those calendars will not be shown in the daily/weekly/monthly calendar view. One or more of your displayed calendars is the culprit in your situation, and turning off their display may be helpful.

You're welcome!

Well done! Good computing!

🤞🏽