Run the New Year setup twice in order to promote the clubbers to their next grade/club appropriately.
For the first/skipped year, pick one week within the starting year in order for the promotions to get run. (For example, for the 2020-2021 club year, pick any date within the August 2020-Dec 2020 timeframe and make it both the Starting and Ending date for that year.)
Once the first/skipped year is created, create the next year using the real club info for the year. At the end of the process, all members will be listed as having not attended at all last year. Ignore the archive option and continue or take the time to go through the names to find and archive members you know will not be returning this year.
As always, the new year will start out with each member's status set as Inactive until they are registered and set as Active.