All you really need is all the field names as your column names in the CSV. You can then use a CSV importer plugin to upload the events.
These are the field names:
event_date
event_end_date
event_cutoff_date
event_desc
event_start
event_finish
event_timezone
event_custom_timezone
event_location
event_address
event_link
event_anchor
event_cost
event_deposit
event_deposittype
event_organiser
event_telephone
event_image
event_redirect
event_registration_message
event_date, event_end_date, event_cutoff_date all need to be timestamps not real dates. Excel can do the conversion for you: https://www.extendoffice.com/documents/excel/2473-excel-timestamp-to-date.html
Just build a CSV with a single event and upload and see what happens.
Graham