Unfortunately, it is not possible. By design, each event can only have one location. If you want to assign multiple locations for one event, you will need to do some customization (need to know programming in order to do that).
I figured as much. I can handle php coding. Can you point me in the right direction as far as the file(s) and/or table(s) where the changes would need to be made?
1. You will need to create an extra database table so that you can store the locations which users selected for one event.
2. You will need to edit the file administrator/components/com_eventbooking/view/event/html.php, change the location dropdown to a multi-select dropdown (maybe see how I process with categories in the same file - an event can have multiple categories)
3. Edit the file administrator/components/com_eventbooking/model.php to store the data for selected locations (same as how I process saving categories).
After completing this task, please let me know and I will guide you for the next step
