I'm trying to add my paychecks into QB for November. It won't let me and says that I need to make the checks for a later date

Paychecks are created directly in QuickBooks payroll integrated with QuickBooks Online on or before your pay date, not afterwards. QuickBooks payroll calculates and tracks the taxes you owe based on the pay period dates. You should contact the QuickBooks payroll team for help. There are limitations to what you can manually enter into the payroll module after the pay date has passed. You may need to create a payroll journal entry. See information on this here: https://quickbooks.intuit.com/learn-support/en-us/journal-entries/manually-enter-payroll-paychecks-i...