Once all transactions are disclosed, all outstanding obligations, debts and expenses are paid, file the last C4. You can review the "Surplus Funds" information on the PDC web site for options if there is money left. If there is outstanding debt, it can be paid via candidate contribution, carried forward to the next campaign. or forgiven. Rules differ between local and judicial candidates and legislative and State office candidates.
If you will no longer be actively using ORCA, you should make a backup of your campaign data and save the backup with your other campaign records for safe keeping.