You will need to run the New Year setup twice, in order to promote the clubbers to their next grade/club appropriately. For the first/skipped year, you only need to pick one week within the starting year, in order for the promotions to get run. (for example, if I'm creating the 2020-2021 club year, I can 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, you can create the next year using your real club info for the year. At the end of the process, all of your members will be listed as having not attended at all last year; but you can just ignore it and continue, or take the time to go through the names to find and archive the members you know will not be returning this year.
As always, the new year will start out with members' statuses set as Inactive, until they are registered and set as Active.