On the schedule maker page, at the bottom of the settings sections, you'll find the copy season or copy tournament button:
This will open a popup with a number of options:
New league / new tournament series
League/Tournament Series is the first part of the name of your event displayed in the header. By checking this box, it will create the new event under a new league, which lets you rename that new league without changing the name of the original event.
This is somewhat less consequential, as you can change it later under settings. If in doubt, just keep this unchecked.
Uncheck this box if you're copying an event for registration purposes or if you'd like to add teams via the bulk team entry tool. Unchecking this box will set up the new event without teams to start.
If you check the copy teams box, you have the option of creating new teams or using the same teams. By using the same teams (unchecking new teams), players on those teams will get carried over and any teams utilizing their team page will be able to continue using it without having to rejoin their team.
Copy registration settings
If your season is set up for registration, you can carry over the registration settings (i.e. prices, free agent pools, custom forms).
Brings your schedule along. This will only show if you have matches on your schedule.
Removes any scores from your games. You'll want to check this if you're copying a schedule to use as the next season's schedule.
By changing the start date, all games will be moved by the same interval from the current start date. E.g. if your schedule's start date is 4/1/2020 and you change it to 3/31/2021 (Monday to Monday) all your games will be shifted by 1 year and you're ready to go.
Making a Backup
If you're copying a schedule to serve as a backup, you'll want to check only copy teams and copy matches.