Google Calendar will give you directions to your event before it starts so you know how to get there.
If
Any event starts
This Trigger fires a set number of minutes before the starting time of any event on your Google Calendar. Note: The time in the ingredient will be based on the timezone set in Google Calendar.
Then
Launch Google Maps Navigation
This Action will launch Google Maps Navigation on your Android device and begin turn-by-turn guidance to the destination you specify.
Explore more great ways to automate Google Calendar and Android Device