It doesn't look like there's a trigger for Google Calendar to accomplish what you're trying to do. For events in an Outlook calender, there is a separate trigger:
But that doesn't seem to exist for Google Calendar, so I'm afraid there's no straightforward workaround to get to your desired end result.
I suppose you could try building a scheduled flow (ie. recurring) that gets all the events from your calendar and then have a condition to check if the start time is in 60 minutes. I don't know which filtering options the 'Get events from google calendar' action supports. Maybe you could specify a filter to only get the events that start within the next hour, and then set the frequency of the flow as desired to get the result the closest to what you want.
I have no experience with the connectors for Google, so I've no idea how feasible this idea is.
